Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1 | :mod:`xml.etree.ElementTree` --- The ElementTree XML API |
| 2 | ======================================================== |
| 3 | |
| 4 | .. module:: xml.etree.ElementTree |
| 5 | :synopsis: Implementation of the ElementTree API. |
Terry Jan Reedy | fa089b9 | 2016-06-11 15:02:54 -0400 | [diff] [blame] | 6 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 7 | .. moduleauthor:: Fredrik Lundh <fredrik@pythonware.com> |
| 8 | |
Terry Jan Reedy | fa089b9 | 2016-06-11 15:02:54 -0400 | [diff] [blame] | 9 | **Source code:** :source:`Lib/xml/etree/ElementTree.py` |
| 10 | |
| 11 | -------------- |
| 12 | |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 13 | The :mod:`xml.etree.ElementTree` module implements a simple and efficient API |
| 14 | for parsing and creating XML data. |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 15 | |
Florent Xicluna | a72a98f | 2012-02-13 11:03:30 +0100 | [diff] [blame] | 16 | .. versionchanged:: 3.3 |
| 17 | This module will use a fast implementation whenever available. |
| 18 | The :mod:`xml.etree.cElementTree` module is deprecated. |
| 19 | |
Christian Heimes | 7380a67 | 2013-03-26 17:35:55 +0100 | [diff] [blame] | 20 | |
| 21 | .. warning:: |
| 22 | |
| 23 | The :mod:`xml.etree.ElementTree` module is not secure against |
| 24 | maliciously constructed data. If you need to parse untrusted or |
| 25 | unauthenticated data see :ref:`xml-vulnerabilities`. |
| 26 | |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 27 | Tutorial |
| 28 | -------- |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 29 | |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 30 | This is a short tutorial for using :mod:`xml.etree.ElementTree` (``ET`` in |
| 31 | short). The goal is to demonstrate some of the building blocks and basic |
| 32 | concepts of the module. |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 33 | |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 34 | XML tree and elements |
| 35 | ^^^^^^^^^^^^^^^^^^^^^ |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 36 | |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 37 | XML is an inherently hierarchical data format, and the most natural way to |
| 38 | represent it is with a tree. ``ET`` has two classes for this purpose - |
| 39 | :class:`ElementTree` represents the whole XML document as a tree, and |
| 40 | :class:`Element` represents a single node in this tree. Interactions with |
| 41 | the whole document (reading and writing to/from files) are usually done |
| 42 | on the :class:`ElementTree` level. Interactions with a single XML element |
| 43 | and its sub-elements are done on the :class:`Element` level. |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 44 | |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 45 | .. _elementtree-parsing-xml: |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 46 | |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 47 | Parsing XML |
| 48 | ^^^^^^^^^^^ |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 49 | |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 50 | We'll be using the following XML document as the sample data for this section: |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 51 | |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 52 | .. code-block:: xml |
| 53 | |
| 54 | <?xml version="1.0"?> |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 55 | <data> |
Eli Bendersky | 3115f0d | 2012-08-15 14:26:30 +0300 | [diff] [blame] | 56 | <country name="Liechtenstein"> |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 57 | <rank>1</rank> |
| 58 | <year>2008</year> |
| 59 | <gdppc>141100</gdppc> |
| 60 | <neighbor name="Austria" direction="E"/> |
| 61 | <neighbor name="Switzerland" direction="W"/> |
| 62 | </country> |
| 63 | <country name="Singapore"> |
| 64 | <rank>4</rank> |
| 65 | <year>2011</year> |
| 66 | <gdppc>59900</gdppc> |
| 67 | <neighbor name="Malaysia" direction="N"/> |
| 68 | </country> |
| 69 | <country name="Panama"> |
| 70 | <rank>68</rank> |
| 71 | <year>2011</year> |
| 72 | <gdppc>13600</gdppc> |
| 73 | <neighbor name="Costa Rica" direction="W"/> |
| 74 | <neighbor name="Colombia" direction="E"/> |
| 75 | </country> |
| 76 | </data> |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 77 | |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 78 | We can import this data by reading from a file:: |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 79 | |
| 80 | import xml.etree.ElementTree as ET |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 81 | tree = ET.parse('country_data.xml') |
| 82 | root = tree.getroot() |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 83 | |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 84 | Or directly from a string:: |
| 85 | |
| 86 | root = ET.fromstring(country_data_as_string) |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 87 | |
| 88 | :func:`fromstring` parses XML from a string directly into an :class:`Element`, |
| 89 | which is the root element of the parsed tree. Other parsing functions may |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 90 | create an :class:`ElementTree`. Check the documentation to be sure. |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 91 | |
| 92 | As an :class:`Element`, ``root`` has a tag and a dictionary of attributes:: |
| 93 | |
| 94 | >>> root.tag |
| 95 | 'data' |
| 96 | >>> root.attrib |
| 97 | {} |
| 98 | |
| 99 | It also has children nodes over which we can iterate:: |
| 100 | |
| 101 | >>> for child in root: |
Serhiy Storchaka | dba9039 | 2016-05-10 12:01:23 +0300 | [diff] [blame] | 102 | ... print(child.tag, child.attrib) |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 103 | ... |
Eli Bendersky | 3115f0d | 2012-08-15 14:26:30 +0300 | [diff] [blame] | 104 | country {'name': 'Liechtenstein'} |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 105 | country {'name': 'Singapore'} |
| 106 | country {'name': 'Panama'} |
| 107 | |
| 108 | Children are nested, and we can access specific child nodes by index:: |
| 109 | |
| 110 | >>> root[0][1].text |
| 111 | '2008' |
| 112 | |
R David Murray | 410d320 | 2014-01-04 23:52:50 -0500 | [diff] [blame] | 113 | |
Eli Bendersky | 0bd22d4 | 2014-04-03 06:14:38 -0700 | [diff] [blame] | 114 | .. note:: |
| 115 | |
| 116 | Not all elements of the XML input will end up as elements of the |
| 117 | parsed tree. Currently, this module skips over any XML comments, |
| 118 | processing instructions, and document type declarations in the |
| 119 | input. Nevertheless, trees built using this module's API rather |
| 120 | than parsing from XML text can have comments and processing |
| 121 | instructions in them; they will be included when generating XML |
| 122 | output. A document type declaration may be accessed by passing a |
| 123 | custom :class:`TreeBuilder` instance to the :class:`XMLParser` |
| 124 | constructor. |
| 125 | |
| 126 | |
R David Murray | 410d320 | 2014-01-04 23:52:50 -0500 | [diff] [blame] | 127 | .. _elementtree-pull-parsing: |
| 128 | |
Eli Bendersky | 2c68e30 | 2013-08-31 07:37:23 -0700 | [diff] [blame] | 129 | Pull API for non-blocking parsing |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 130 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ |
Eli Bendersky | 3bdead1 | 2013-04-20 09:06:27 -0700 | [diff] [blame] | 131 | |
R David Murray | 410d320 | 2014-01-04 23:52:50 -0500 | [diff] [blame] | 132 | Most parsing functions provided by this module require the whole document |
| 133 | to be read at once before returning any result. It is possible to use an |
| 134 | :class:`XMLParser` and feed data into it incrementally, but it is a push API that |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 135 | calls methods on a callback target, which is too low-level and inconvenient for |
| 136 | most needs. Sometimes what the user really wants is to be able to parse XML |
| 137 | incrementally, without blocking operations, while enjoying the convenience of |
| 138 | fully constructed :class:`Element` objects. |
Eli Bendersky | 3bdead1 | 2013-04-20 09:06:27 -0700 | [diff] [blame] | 139 | |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 140 | The most powerful tool for doing this is :class:`XMLPullParser`. It does not |
| 141 | require a blocking read to obtain the XML data, and is instead fed with data |
| 142 | incrementally with :meth:`XMLPullParser.feed` calls. To get the parsed XML |
R David Murray | 410d320 | 2014-01-04 23:52:50 -0500 | [diff] [blame] | 143 | elements, call :meth:`XMLPullParser.read_events`. Here is an example:: |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 144 | |
Eli Bendersky | 2c68e30 | 2013-08-31 07:37:23 -0700 | [diff] [blame] | 145 | >>> parser = ET.XMLPullParser(['start', 'end']) |
| 146 | >>> parser.feed('<mytag>sometext') |
| 147 | >>> list(parser.read_events()) |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 148 | [('start', <Element 'mytag' at 0x7fa66db2be58>)] |
Eli Bendersky | 2c68e30 | 2013-08-31 07:37:23 -0700 | [diff] [blame] | 149 | >>> parser.feed(' more text</mytag>') |
| 150 | >>> for event, elem in parser.read_events(): |
Serhiy Storchaka | dba9039 | 2016-05-10 12:01:23 +0300 | [diff] [blame] | 151 | ... print(event) |
| 152 | ... print(elem.tag, 'text=', elem.text) |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 153 | ... |
| 154 | end |
Eli Bendersky | 3bdead1 | 2013-04-20 09:06:27 -0700 | [diff] [blame] | 155 | |
Eli Bendersky | 2c68e30 | 2013-08-31 07:37:23 -0700 | [diff] [blame] | 156 | The obvious use case is applications that operate in a non-blocking fashion |
Eli Bendersky | 3bdead1 | 2013-04-20 09:06:27 -0700 | [diff] [blame] | 157 | where the XML data is being received from a socket or read incrementally from |
| 158 | some storage device. In such cases, blocking reads are unacceptable. |
| 159 | |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 160 | Because it's so flexible, :class:`XMLPullParser` can be inconvenient to use for |
| 161 | simpler use-cases. If you don't mind your application blocking on reading XML |
| 162 | data but would still like to have incremental parsing capabilities, take a look |
| 163 | at :func:`iterparse`. It can be useful when you're reading a large XML document |
| 164 | and don't want to hold it wholly in memory. |
Eli Bendersky | 3bdead1 | 2013-04-20 09:06:27 -0700 | [diff] [blame] | 165 | |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 166 | Finding interesting elements |
| 167 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ |
| 168 | |
| 169 | :class:`Element` has some useful methods that help iterate recursively over all |
| 170 | the sub-tree below it (its children, their children, and so on). For example, |
| 171 | :meth:`Element.iter`:: |
| 172 | |
| 173 | >>> for neighbor in root.iter('neighbor'): |
Serhiy Storchaka | dba9039 | 2016-05-10 12:01:23 +0300 | [diff] [blame] | 174 | ... print(neighbor.attrib) |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 175 | ... |
| 176 | {'name': 'Austria', 'direction': 'E'} |
| 177 | {'name': 'Switzerland', 'direction': 'W'} |
| 178 | {'name': 'Malaysia', 'direction': 'N'} |
| 179 | {'name': 'Costa Rica', 'direction': 'W'} |
| 180 | {'name': 'Colombia', 'direction': 'E'} |
| 181 | |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 182 | :meth:`Element.findall` finds only elements with a tag which are direct |
| 183 | children of the current element. :meth:`Element.find` finds the *first* child |
Georg Brandl | bdaee3a | 2013-10-06 09:23:03 +0200 | [diff] [blame] | 184 | with a particular tag, and :attr:`Element.text` accesses the element's text |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 185 | content. :meth:`Element.get` accesses the element's attributes:: |
| 186 | |
| 187 | >>> for country in root.findall('country'): |
Serhiy Storchaka | dba9039 | 2016-05-10 12:01:23 +0300 | [diff] [blame] | 188 | ... rank = country.find('rank').text |
| 189 | ... name = country.get('name') |
| 190 | ... print(name, rank) |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 191 | ... |
Eli Bendersky | 3115f0d | 2012-08-15 14:26:30 +0300 | [diff] [blame] | 192 | Liechtenstein 1 |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 193 | Singapore 4 |
| 194 | Panama 68 |
| 195 | |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 196 | More sophisticated specification of which elements to look for is possible by |
| 197 | using :ref:`XPath <elementtree-xpath>`. |
| 198 | |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 199 | Modifying an XML File |
| 200 | ^^^^^^^^^^^^^^^^^^^^^ |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 201 | |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 202 | :class:`ElementTree` provides a simple way to build XML documents and write them to files. |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 203 | The :meth:`ElementTree.write` method serves this purpose. |
| 204 | |
| 205 | Once created, an :class:`Element` object may be manipulated by directly changing |
| 206 | its fields (such as :attr:`Element.text`), adding and modifying attributes |
| 207 | (:meth:`Element.set` method), as well as adding new children (for example |
| 208 | with :meth:`Element.append`). |
| 209 | |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 210 | Let's say we want to add one to each country's rank, and add an ``updated`` |
| 211 | attribute to the rank element:: |
| 212 | |
| 213 | >>> for rank in root.iter('rank'): |
Serhiy Storchaka | dba9039 | 2016-05-10 12:01:23 +0300 | [diff] [blame] | 214 | ... new_rank = int(rank.text) + 1 |
| 215 | ... rank.text = str(new_rank) |
| 216 | ... rank.set('updated', 'yes') |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 217 | ... |
Eli Bendersky | a1b0f6d | 2012-08-18 05:42:22 +0300 | [diff] [blame] | 218 | >>> tree.write('output.xml') |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 219 | |
| 220 | Our XML now looks like this: |
| 221 | |
| 222 | .. code-block:: xml |
| 223 | |
| 224 | <?xml version="1.0"?> |
| 225 | <data> |
Eli Bendersky | 3115f0d | 2012-08-15 14:26:30 +0300 | [diff] [blame] | 226 | <country name="Liechtenstein"> |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 227 | <rank updated="yes">2</rank> |
| 228 | <year>2008</year> |
| 229 | <gdppc>141100</gdppc> |
| 230 | <neighbor name="Austria" direction="E"/> |
| 231 | <neighbor name="Switzerland" direction="W"/> |
| 232 | </country> |
| 233 | <country name="Singapore"> |
| 234 | <rank updated="yes">5</rank> |
| 235 | <year>2011</year> |
| 236 | <gdppc>59900</gdppc> |
| 237 | <neighbor name="Malaysia" direction="N"/> |
| 238 | </country> |
| 239 | <country name="Panama"> |
| 240 | <rank updated="yes">69</rank> |
| 241 | <year>2011</year> |
| 242 | <gdppc>13600</gdppc> |
| 243 | <neighbor name="Costa Rica" direction="W"/> |
| 244 | <neighbor name="Colombia" direction="E"/> |
| 245 | </country> |
| 246 | </data> |
| 247 | |
| 248 | We can remove elements using :meth:`Element.remove`. Let's say we want to |
| 249 | remove all countries with a rank higher than 50:: |
| 250 | |
| 251 | >>> for country in root.findall('country'): |
Serhiy Storchaka | dba9039 | 2016-05-10 12:01:23 +0300 | [diff] [blame] | 252 | ... rank = int(country.find('rank').text) |
| 253 | ... if rank > 50: |
| 254 | ... root.remove(country) |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 255 | ... |
Eli Bendersky | a1b0f6d | 2012-08-18 05:42:22 +0300 | [diff] [blame] | 256 | >>> tree.write('output.xml') |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 257 | |
| 258 | Our XML now looks like this: |
| 259 | |
| 260 | .. code-block:: xml |
| 261 | |
| 262 | <?xml version="1.0"?> |
| 263 | <data> |
Eli Bendersky | 3115f0d | 2012-08-15 14:26:30 +0300 | [diff] [blame] | 264 | <country name="Liechtenstein"> |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 265 | <rank updated="yes">2</rank> |
| 266 | <year>2008</year> |
| 267 | <gdppc>141100</gdppc> |
| 268 | <neighbor name="Austria" direction="E"/> |
| 269 | <neighbor name="Switzerland" direction="W"/> |
| 270 | </country> |
| 271 | <country name="Singapore"> |
| 272 | <rank updated="yes">5</rank> |
| 273 | <year>2011</year> |
| 274 | <gdppc>59900</gdppc> |
| 275 | <neighbor name="Malaysia" direction="N"/> |
| 276 | </country> |
| 277 | </data> |
| 278 | |
| 279 | Building XML documents |
| 280 | ^^^^^^^^^^^^^^^^^^^^^^ |
| 281 | |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 282 | The :func:`SubElement` function also provides a convenient way to create new |
| 283 | sub-elements for a given element:: |
| 284 | |
| 285 | >>> a = ET.Element('a') |
| 286 | >>> b = ET.SubElement(a, 'b') |
| 287 | >>> c = ET.SubElement(a, 'c') |
| 288 | >>> d = ET.SubElement(c, 'd') |
| 289 | >>> ET.dump(a) |
| 290 | <a><b /><c><d /></c></a> |
| 291 | |
Raymond Hettinger | f6e31b7 | 2015-03-22 15:29:09 -0700 | [diff] [blame] | 292 | Parsing XML with Namespaces |
| 293 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ |
| 294 | |
| 295 | If the XML input has `namespaces |
| 296 | <https://en.wikipedia.org/wiki/XML_namespace>`__, tags and attributes |
| 297 | with prefixes in the form ``prefix:sometag`` get expanded to |
Raymond Hettinger | c43a666 | 2015-03-30 20:29:28 -0700 | [diff] [blame] | 298 | ``{uri}sometag`` where the *prefix* is replaced by the full *URI*. |
| 299 | Also, if there is a `default namespace |
sblondon | 8d1f2f4 | 2018-02-10 23:39:43 +0100 | [diff] [blame] | 300 | <https://www.w3.org/TR/xml-names/#defaulting>`__, |
Raymond Hettinger | f6e31b7 | 2015-03-22 15:29:09 -0700 | [diff] [blame] | 301 | that full URI gets prepended to all of the non-prefixed tags. |
| 302 | |
| 303 | Here is an XML example that incorporates two namespaces, one with the |
| 304 | prefix "fictional" and the other serving as the default namespace: |
| 305 | |
| 306 | .. code-block:: xml |
| 307 | |
| 308 | <?xml version="1.0"?> |
| 309 | <actors xmlns:fictional="http://characters.example.com" |
| 310 | xmlns="http://people.example.com"> |
| 311 | <actor> |
| 312 | <name>John Cleese</name> |
| 313 | <fictional:character>Lancelot</fictional:character> |
| 314 | <fictional:character>Archie Leach</fictional:character> |
| 315 | </actor> |
| 316 | <actor> |
| 317 | <name>Eric Idle</name> |
| 318 | <fictional:character>Sir Robin</fictional:character> |
| 319 | <fictional:character>Gunther</fictional:character> |
| 320 | <fictional:character>Commander Clement</fictional:character> |
| 321 | </actor> |
| 322 | </actors> |
| 323 | |
| 324 | One way to search and explore this XML example is to manually add the |
Raymond Hettinger | c43a666 | 2015-03-30 20:29:28 -0700 | [diff] [blame] | 325 | URI to every tag or attribute in the xpath of a |
| 326 | :meth:`~Element.find` or :meth:`~Element.findall`:: |
Raymond Hettinger | f6e31b7 | 2015-03-22 15:29:09 -0700 | [diff] [blame] | 327 | |
Raymond Hettinger | c43a666 | 2015-03-30 20:29:28 -0700 | [diff] [blame] | 328 | root = fromstring(xml_text) |
Raymond Hettinger | f6e31b7 | 2015-03-22 15:29:09 -0700 | [diff] [blame] | 329 | for actor in root.findall('{http://people.example.com}actor'): |
| 330 | name = actor.find('{http://people.example.com}name') |
| 331 | print(name.text) |
| 332 | for char in actor.findall('{http://characters.example.com}character'): |
| 333 | print(' |-->', char.text) |
| 334 | |
Raymond Hettinger | c43a666 | 2015-03-30 20:29:28 -0700 | [diff] [blame] | 335 | A better way to search the namespaced XML example is to create a |
| 336 | dictionary with your own prefixes and use those in the search functions:: |
Raymond Hettinger | f6e31b7 | 2015-03-22 15:29:09 -0700 | [diff] [blame] | 337 | |
| 338 | ns = {'real_person': 'http://people.example.com', |
| 339 | 'role': 'http://characters.example.com'} |
| 340 | |
| 341 | for actor in root.findall('real_person:actor', ns): |
| 342 | name = actor.find('real_person:name', ns) |
| 343 | print(name.text) |
| 344 | for char in actor.findall('role:character', ns): |
| 345 | print(' |-->', char.text) |
| 346 | |
| 347 | These two approaches both output:: |
| 348 | |
| 349 | John Cleese |
| 350 | |--> Lancelot |
| 351 | |--> Archie Leach |
| 352 | Eric Idle |
| 353 | |--> Sir Robin |
| 354 | |--> Gunther |
| 355 | |--> Commander Clement |
| 356 | |
| 357 | |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 358 | Additional resources |
| 359 | ^^^^^^^^^^^^^^^^^^^^ |
| 360 | |
| 361 | See http://effbot.org/zone/element-index.htm for tutorials and links to other |
| 362 | docs. |
| 363 | |
| 364 | |
| 365 | .. _elementtree-xpath: |
| 366 | |
| 367 | XPath support |
| 368 | ------------- |
| 369 | |
| 370 | This module provides limited support for |
Serhiy Storchaka | 6dff020 | 2016-05-07 10:49:07 +0300 | [diff] [blame] | 371 | `XPath expressions <https://www.w3.org/TR/xpath>`_ for locating elements in a |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 372 | tree. The goal is to support a small subset of the abbreviated syntax; a full |
| 373 | XPath engine is outside the scope of the module. |
| 374 | |
| 375 | Example |
| 376 | ^^^^^^^ |
| 377 | |
| 378 | Here's an example that demonstrates some of the XPath capabilities of the |
| 379 | module. We'll be using the ``countrydata`` XML document from the |
| 380 | :ref:`Parsing XML <elementtree-parsing-xml>` section:: |
| 381 | |
| 382 | import xml.etree.ElementTree as ET |
| 383 | |
| 384 | root = ET.fromstring(countrydata) |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 385 | |
| 386 | # Top-level elements |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 387 | root.findall(".") |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 388 | |
| 389 | # All 'neighbor' grand-children of 'country' children of the top-level |
| 390 | # elements |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 391 | root.findall("./country/neighbor") |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 392 | |
| 393 | # Nodes with name='Singapore' that have a 'year' child |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 394 | root.findall(".//year/..[@name='Singapore']") |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 395 | |
| 396 | # 'year' nodes that are children of nodes with name='Singapore' |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 397 | root.findall(".//*[@name='Singapore']/year") |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 398 | |
| 399 | # All 'neighbor' nodes that are the second child of their parent |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 400 | root.findall(".//neighbor[2]") |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 401 | |
| 402 | Supported XPath syntax |
| 403 | ^^^^^^^^^^^^^^^^^^^^^^ |
| 404 | |
Georg Brandl | 44ea77b | 2013-03-28 13:28:44 +0100 | [diff] [blame] | 405 | .. tabularcolumns:: |l|L| |
| 406 | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 407 | +-----------------------+------------------------------------------------------+ |
| 408 | | Syntax | Meaning | |
| 409 | +=======================+======================================================+ |
| 410 | | ``tag`` | Selects all child elements with the given tag. | |
| 411 | | | For example, ``spam`` selects all child elements | |
Raymond Hettinger | 1e1e601 | 2014-03-29 11:50:08 -0700 | [diff] [blame] | 412 | | | named ``spam``, and ``spam/egg`` selects all | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 413 | | | grandchildren named ``egg`` in all children named | |
| 414 | | | ``spam``. | |
| 415 | +-----------------------+------------------------------------------------------+ |
| 416 | | ``*`` | Selects all child elements. For example, ``*/egg`` | |
| 417 | | | selects all grandchildren named ``egg``. | |
| 418 | +-----------------------+------------------------------------------------------+ |
| 419 | | ``.`` | Selects the current node. This is mostly useful | |
| 420 | | | at the beginning of the path, to indicate that it's | |
| 421 | | | a relative path. | |
| 422 | +-----------------------+------------------------------------------------------+ |
| 423 | | ``//`` | Selects all subelements, on all levels beneath the | |
Eli Bendersky | ede001a | 2012-03-27 04:57:23 +0200 | [diff] [blame] | 424 | | | current element. For example, ``.//egg`` selects | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 425 | | | all ``egg`` elements in the entire tree. | |
| 426 | +-----------------------+------------------------------------------------------+ |
Eli Bendersky | 323a43a | 2012-10-09 06:46:33 -0700 | [diff] [blame] | 427 | | ``..`` | Selects the parent element. Returns ``None`` if the | |
| 428 | | | path attempts to reach the ancestors of the start | |
| 429 | | | element (the element ``find`` was called on). | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 430 | +-----------------------+------------------------------------------------------+ |
| 431 | | ``[@attrib]`` | Selects all elements that have the given attribute. | |
| 432 | +-----------------------+------------------------------------------------------+ |
| 433 | | ``[@attrib='value']`` | Selects all elements for which the given attribute | |
| 434 | | | has the given value. The value cannot contain | |
| 435 | | | quotes. | |
| 436 | +-----------------------+------------------------------------------------------+ |
| 437 | | ``[tag]`` | Selects all elements that have a child named | |
| 438 | | | ``tag``. Only immediate children are supported. | |
| 439 | +-----------------------+------------------------------------------------------+ |
scoder | 101a5e8 | 2017-09-30 15:35:21 +0200 | [diff] [blame] | 440 | | ``[.='text']`` | Selects all elements whose complete text content, | |
| 441 | | | including descendants, equals the given ``text``. | |
| 442 | | | | |
| 443 | | | .. versionadded:: 3.7 | |
| 444 | +-----------------------+------------------------------------------------------+ |
Raymond Hettinger | c43a666 | 2015-03-30 20:29:28 -0700 | [diff] [blame] | 445 | | ``[tag='text']`` | Selects all elements that have a child named | |
| 446 | | | ``tag`` whose complete text content, including | |
| 447 | | | descendants, equals the given ``text``. | |
Raymond Hettinger | f6e31b7 | 2015-03-22 15:29:09 -0700 | [diff] [blame] | 448 | +-----------------------+------------------------------------------------------+ |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 449 | | ``[position]`` | Selects all elements that are located at the given | |
| 450 | | | position. The position can be either an integer | |
| 451 | | | (1 is the first position), the expression ``last()`` | |
| 452 | | | (for the last position), or a position relative to | |
| 453 | | | the last position (e.g. ``last()-1``). | |
| 454 | +-----------------------+------------------------------------------------------+ |
| 455 | |
| 456 | Predicates (expressions within square brackets) must be preceded by a tag |
| 457 | name, an asterisk, or another predicate. ``position`` predicates must be |
| 458 | preceded by a tag name. |
| 459 | |
| 460 | Reference |
| 461 | --------- |
| 462 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 463 | .. _elementtree-functions: |
| 464 | |
| 465 | Functions |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 466 | ^^^^^^^^^ |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 467 | |
| 468 | |
Georg Brandl | 7f01a13 | 2009-09-16 15:58:14 +0000 | [diff] [blame] | 469 | .. function:: Comment(text=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 470 | |
Georg Brandl | f694518 | 2008-02-01 11:56:49 +0000 | [diff] [blame] | 471 | Comment element factory. This factory function creates a special element |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 472 | that will be serialized as an XML comment by the standard serializer. The |
| 473 | comment string can be either a bytestring or a Unicode string. *text* is a |
| 474 | string containing the comment string. Returns an element instance |
Georg Brandl | f694518 | 2008-02-01 11:56:49 +0000 | [diff] [blame] | 475 | representing a comment. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 476 | |
Eli Bendersky | 0bd22d4 | 2014-04-03 06:14:38 -0700 | [diff] [blame] | 477 | Note that :class:`XMLParser` skips over comments in the input |
| 478 | instead of creating comment objects for them. An :class:`ElementTree` will |
| 479 | only contain comment nodes if they have been inserted into to |
| 480 | the tree using one of the :class:`Element` methods. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 481 | |
| 482 | .. function:: dump(elem) |
| 483 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 484 | Writes an element tree or element structure to sys.stdout. This function |
| 485 | should be used for debugging only. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 486 | |
| 487 | The exact output format is implementation dependent. In this version, it's |
| 488 | written as an ordinary XML file. |
| 489 | |
| 490 | *elem* is an element tree or an individual element. |
| 491 | |
| 492 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 493 | .. function:: fromstring(text) |
| 494 | |
Florent Xicluna | dddd5e9 | 2010-03-14 01:28:07 +0000 | [diff] [blame] | 495 | Parses an XML section from a string constant. Same as :func:`XML`. *text* |
| 496 | is a string containing XML data. Returns an :class:`Element` instance. |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 497 | |
| 498 | |
| 499 | .. function:: fromstringlist(sequence, parser=None) |
| 500 | |
| 501 | Parses an XML document from a sequence of string fragments. *sequence* is a |
| 502 | list or other sequence containing XML data fragments. *parser* is an |
| 503 | optional parser instance. If not given, the standard :class:`XMLParser` |
| 504 | parser is used. Returns an :class:`Element` instance. |
| 505 | |
Ezio Melotti | f8754a6 | 2010-03-21 07:16:43 +0000 | [diff] [blame] | 506 | .. versionadded:: 3.2 |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 507 | |
| 508 | |
| 509 | .. function:: iselement(element) |
| 510 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 511 | Checks if an object appears to be a valid element object. *element* is an |
| 512 | element instance. Returns a true value if this is an element object. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 513 | |
| 514 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 515 | .. function:: iterparse(source, events=None, parser=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 516 | |
| 517 | Parses an XML section into an element tree incrementally, and reports what's |
Eli Bendersky | 604c4ff | 2012-03-16 08:41:30 +0200 | [diff] [blame] | 518 | going on to the user. *source* is a filename or :term:`file object` |
Eli Bendersky | fb62544 | 2013-05-19 09:09:24 -0700 | [diff] [blame] | 519 | containing XML data. *events* is a sequence of events to report back. The |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 520 | supported events are the strings ``"start"``, ``"end"``, ``"start-ns"`` and |
| 521 | ``"end-ns"`` (the "ns" events are used to get detailed namespace |
Eli Bendersky | 604c4ff | 2012-03-16 08:41:30 +0200 | [diff] [blame] | 522 | information). If *events* is omitted, only ``"end"`` events are reported. |
| 523 | *parser* is an optional parser instance. If not given, the standard |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 524 | :class:`XMLParser` parser is used. *parser* must be a subclass of |
| 525 | :class:`XMLParser` and can only use the default :class:`TreeBuilder` as a |
| 526 | target. Returns an :term:`iterator` providing ``(event, elem)`` pairs. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 527 | |
Eli Bendersky | ab2a76c | 2013-04-20 05:53:50 -0700 | [diff] [blame] | 528 | Note that while :func:`iterparse` builds the tree incrementally, it issues |
| 529 | blocking reads on *source* (or the file it names). As such, it's unsuitable |
Eli Bendersky | 2c68e30 | 2013-08-31 07:37:23 -0700 | [diff] [blame] | 530 | for applications where blocking reads can't be made. For fully non-blocking |
| 531 | parsing, see :class:`XMLPullParser`. |
Eli Bendersky | ab2a76c | 2013-04-20 05:53:50 -0700 | [diff] [blame] | 532 | |
Benjamin Peterson | 75edad0 | 2009-01-01 15:05:06 +0000 | [diff] [blame] | 533 | .. note:: |
| 534 | |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 535 | :func:`iterparse` only guarantees that it has seen the ">" character of a |
| 536 | starting tag when it emits a "start" event, so the attributes are defined, |
| 537 | but the contents of the text and tail attributes are undefined at that |
| 538 | point. The same applies to the element children; they may or may not be |
| 539 | present. |
Benjamin Peterson | 75edad0 | 2009-01-01 15:05:06 +0000 | [diff] [blame] | 540 | |
| 541 | If you need a fully populated element, look for "end" events instead. |
| 542 | |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 543 | .. deprecated:: 3.4 |
| 544 | The *parser* argument. |
| 545 | |
Georg Brandl | 7f01a13 | 2009-09-16 15:58:14 +0000 | [diff] [blame] | 546 | .. function:: parse(source, parser=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 547 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 548 | Parses an XML section into an element tree. *source* is a filename or file |
| 549 | object containing XML data. *parser* is an optional parser instance. If |
| 550 | not given, the standard :class:`XMLParser` parser is used. Returns an |
| 551 | :class:`ElementTree` instance. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 552 | |
| 553 | |
Georg Brandl | 7f01a13 | 2009-09-16 15:58:14 +0000 | [diff] [blame] | 554 | .. function:: ProcessingInstruction(target, text=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 555 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 556 | PI element factory. This factory function creates a special element that |
| 557 | will be serialized as an XML processing instruction. *target* is a string |
| 558 | containing the PI target. *text* is a string containing the PI contents, if |
| 559 | given. Returns an element instance, representing a processing instruction. |
| 560 | |
Eli Bendersky | 0bd22d4 | 2014-04-03 06:14:38 -0700 | [diff] [blame] | 561 | Note that :class:`XMLParser` skips over processing instructions |
| 562 | in the input instead of creating comment objects for them. An |
| 563 | :class:`ElementTree` will only contain processing instruction nodes if |
| 564 | they have been inserted into to the tree using one of the |
| 565 | :class:`Element` methods. |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 566 | |
| 567 | .. function:: register_namespace(prefix, uri) |
| 568 | |
| 569 | Registers a namespace prefix. The registry is global, and any existing |
| 570 | mapping for either the given prefix or the namespace URI will be removed. |
| 571 | *prefix* is a namespace prefix. *uri* is a namespace uri. Tags and |
| 572 | attributes in this namespace will be serialized with the given prefix, if at |
| 573 | all possible. |
| 574 | |
Ezio Melotti | f8754a6 | 2010-03-21 07:16:43 +0000 | [diff] [blame] | 575 | .. versionadded:: 3.2 |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 576 | |
| 577 | |
Georg Brandl | 7f01a13 | 2009-09-16 15:58:14 +0000 | [diff] [blame] | 578 | .. function:: SubElement(parent, tag, attrib={}, **extra) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 579 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 580 | Subelement factory. This function creates an element instance, and appends |
| 581 | it to an existing element. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 582 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 583 | The element name, attribute names, and attribute values can be either |
| 584 | bytestrings or Unicode strings. *parent* is the parent element. *tag* is |
| 585 | the subelement name. *attrib* is an optional dictionary, containing element |
| 586 | attributes. *extra* contains additional attributes, given as keyword |
| 587 | arguments. Returns an element instance. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 588 | |
| 589 | |
Serhiy Storchaka | 9e189f0 | 2013-01-13 22:24:27 +0200 | [diff] [blame] | 590 | .. function:: tostring(element, encoding="us-ascii", method="xml", *, \ |
Eli Bendersky | a9a2ef5 | 2013-01-13 06:04:43 -0800 | [diff] [blame] | 591 | short_empty_elements=True) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 592 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 593 | Generates a string representation of an XML element, including all |
Florent Xicluna | dddd5e9 | 2010-03-14 01:28:07 +0000 | [diff] [blame] | 594 | subelements. *element* is an :class:`Element` instance. *encoding* [1]_ is |
Florent Xicluna | c17f172 | 2010-08-08 19:48:29 +0000 | [diff] [blame] | 595 | the output encoding (default is US-ASCII). Use ``encoding="unicode"`` to |
Eli Bendersky | 831893a | 2012-10-09 07:18:16 -0700 | [diff] [blame] | 596 | generate a Unicode string (otherwise, a bytestring is generated). *method* |
| 597 | is either ``"xml"``, ``"html"`` or ``"text"`` (default is ``"xml"``). |
Eli Bendersky | a9a2ef5 | 2013-01-13 06:04:43 -0800 | [diff] [blame] | 598 | *short_empty_elements* has the same meaning as in :meth:`ElementTree.write`. |
Eli Bendersky | 831893a | 2012-10-09 07:18:16 -0700 | [diff] [blame] | 599 | Returns an (optionally) encoded string containing the XML data. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 600 | |
Eli Bendersky | a9a2ef5 | 2013-01-13 06:04:43 -0800 | [diff] [blame] | 601 | .. versionadded:: 3.4 |
| 602 | The *short_empty_elements* parameter. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 603 | |
Eli Bendersky | a9a2ef5 | 2013-01-13 06:04:43 -0800 | [diff] [blame] | 604 | |
Serhiy Storchaka | 9e189f0 | 2013-01-13 22:24:27 +0200 | [diff] [blame] | 605 | .. function:: tostringlist(element, encoding="us-ascii", method="xml", *, \ |
Eli Bendersky | a9a2ef5 | 2013-01-13 06:04:43 -0800 | [diff] [blame] | 606 | short_empty_elements=True) |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 607 | |
| 608 | Generates a string representation of an XML element, including all |
Florent Xicluna | dddd5e9 | 2010-03-14 01:28:07 +0000 | [diff] [blame] | 609 | subelements. *element* is an :class:`Element` instance. *encoding* [1]_ is |
Florent Xicluna | c17f172 | 2010-08-08 19:48:29 +0000 | [diff] [blame] | 610 | the output encoding (default is US-ASCII). Use ``encoding="unicode"`` to |
Eli Bendersky | 831893a | 2012-10-09 07:18:16 -0700 | [diff] [blame] | 611 | generate a Unicode string (otherwise, a bytestring is generated). *method* |
| 612 | is either ``"xml"``, ``"html"`` or ``"text"`` (default is ``"xml"``). |
Eli Bendersky | a9a2ef5 | 2013-01-13 06:04:43 -0800 | [diff] [blame] | 613 | *short_empty_elements* has the same meaning as in :meth:`ElementTree.write`. |
Eli Bendersky | 831893a | 2012-10-09 07:18:16 -0700 | [diff] [blame] | 614 | Returns a list of (optionally) encoded strings containing the XML data. |
| 615 | It does not guarantee any specific sequence, except that |
Serhiy Storchaka | 5e028ae | 2014-02-06 21:10:41 +0200 | [diff] [blame] | 616 | ``b"".join(tostringlist(element)) == tostring(element)``. |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 617 | |
Ezio Melotti | f8754a6 | 2010-03-21 07:16:43 +0000 | [diff] [blame] | 618 | .. versionadded:: 3.2 |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 619 | |
Eli Bendersky | a9a2ef5 | 2013-01-13 06:04:43 -0800 | [diff] [blame] | 620 | .. versionadded:: 3.4 |
| 621 | The *short_empty_elements* parameter. |
| 622 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 623 | |
| 624 | .. function:: XML(text, parser=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 625 | |
| 626 | Parses an XML section from a string constant. This function can be used to |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 627 | embed "XML literals" in Python code. *text* is a string containing XML |
| 628 | data. *parser* is an optional parser instance. If not given, the standard |
| 629 | :class:`XMLParser` parser is used. Returns an :class:`Element` instance. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 630 | |
| 631 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 632 | .. function:: XMLID(text, parser=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 633 | |
| 634 | Parses an XML section from a string constant, and also returns a dictionary |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 635 | which maps from element id:s to elements. *text* is a string containing XML |
| 636 | data. *parser* is an optional parser instance. If not given, the standard |
| 637 | :class:`XMLParser` parser is used. Returns a tuple containing an |
| 638 | :class:`Element` instance and a dictionary. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 639 | |
| 640 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 641 | .. _elementtree-element-objects: |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 642 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 643 | Element Objects |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 644 | ^^^^^^^^^^^^^^^ |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 645 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 646 | .. class:: Element(tag, attrib={}, **extra) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 647 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 648 | Element class. This class defines the Element interface, and provides a |
| 649 | reference implementation of this interface. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 650 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 651 | The element name, attribute names, and attribute values can be either |
| 652 | bytestrings or Unicode strings. *tag* is the element name. *attrib* is |
| 653 | an optional dictionary, containing element attributes. *extra* contains |
| 654 | additional attributes, given as keyword arguments. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 655 | |
| 656 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 657 | .. attribute:: tag |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 658 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 659 | A string identifying what kind of data this element represents (the |
| 660 | element type, in other words). |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 661 | |
| 662 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 663 | .. attribute:: text |
Ned Deily | eca0445 | 2015-08-17 22:11:17 -0400 | [diff] [blame] | 664 | tail |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 665 | |
Ned Deily | eca0445 | 2015-08-17 22:11:17 -0400 | [diff] [blame] | 666 | These attributes can be used to hold additional data associated with |
| 667 | the element. Their values are usually strings but may be any |
| 668 | application-specific object. If the element is created from |
| 669 | an XML file, the *text* attribute holds either the text between |
| 670 | the element's start tag and its first child or end tag, or ``None``, and |
| 671 | the *tail* attribute holds either the text between the element's |
| 672 | end tag and the next tag, or ``None``. For the XML data |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 673 | |
Ned Deily | eca0445 | 2015-08-17 22:11:17 -0400 | [diff] [blame] | 674 | .. code-block:: xml |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 675 | |
Ned Deily | eca0445 | 2015-08-17 22:11:17 -0400 | [diff] [blame] | 676 | <a><b>1<c>2<d/>3</c></b>4</a> |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 677 | |
Ned Deily | eca0445 | 2015-08-17 22:11:17 -0400 | [diff] [blame] | 678 | the *a* element has ``None`` for both *text* and *tail* attributes, |
| 679 | the *b* element has *text* ``"1"`` and *tail* ``"4"``, |
| 680 | the *c* element has *text* ``"2"`` and *tail* ``None``, |
| 681 | and the *d* element has *text* ``None`` and *tail* ``"3"``. |
| 682 | |
| 683 | To collect the inner text of an element, see :meth:`itertext`, for |
| 684 | example ``"".join(element.itertext())``. |
| 685 | |
| 686 | Applications may store arbitrary objects in these attributes. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 687 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 688 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 689 | .. attribute:: attrib |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 690 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 691 | A dictionary containing the element's attributes. Note that while the |
| 692 | *attrib* value is always a real mutable Python dictionary, an ElementTree |
| 693 | implementation may choose to use another internal representation, and |
| 694 | create the dictionary only if someone asks for it. To take advantage of |
| 695 | such implementations, use the dictionary methods below whenever possible. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 696 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 697 | The following dictionary-like methods work on the element attributes. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 698 | |
| 699 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 700 | .. method:: clear() |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 701 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 702 | Resets an element. This function removes all subelements, clears all |
Eli Bendersky | 323a43a | 2012-10-09 06:46:33 -0700 | [diff] [blame] | 703 | attributes, and sets the text and tail attributes to ``None``. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 704 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 705 | |
| 706 | .. method:: get(key, default=None) |
| 707 | |
| 708 | Gets the element attribute named *key*. |
| 709 | |
| 710 | Returns the attribute value, or *default* if the attribute was not found. |
| 711 | |
| 712 | |
| 713 | .. method:: items() |
| 714 | |
| 715 | Returns the element attributes as a sequence of (name, value) pairs. The |
| 716 | attributes are returned in an arbitrary order. |
| 717 | |
| 718 | |
| 719 | .. method:: keys() |
| 720 | |
| 721 | Returns the elements attribute names as a list. The names are returned |
| 722 | in an arbitrary order. |
| 723 | |
| 724 | |
| 725 | .. method:: set(key, value) |
| 726 | |
| 727 | Set the attribute *key* on the element to *value*. |
| 728 | |
| 729 | The following methods work on the element's children (subelements). |
| 730 | |
| 731 | |
| 732 | .. method:: append(subelement) |
| 733 | |
Eli Bendersky | 396e8fc | 2012-03-23 14:24:20 +0200 | [diff] [blame] | 734 | Adds the element *subelement* to the end of this element's internal list |
| 735 | of subelements. Raises :exc:`TypeError` if *subelement* is not an |
| 736 | :class:`Element`. |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 737 | |
| 738 | |
| 739 | .. method:: extend(subelements) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 740 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 741 | Appends *subelements* from a sequence object with zero or more elements. |
Eli Bendersky | 396e8fc | 2012-03-23 14:24:20 +0200 | [diff] [blame] | 742 | Raises :exc:`TypeError` if a subelement is not an :class:`Element`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 743 | |
Ezio Melotti | f8754a6 | 2010-03-21 07:16:43 +0000 | [diff] [blame] | 744 | .. versionadded:: 3.2 |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 745 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 746 | |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 747 | .. method:: find(match, namespaces=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 748 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 749 | Finds the first subelement matching *match*. *match* may be a tag name |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 750 | or a :ref:`path <elementtree-xpath>`. Returns an element instance |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 751 | or ``None``. *namespaces* is an optional mapping from namespace prefix |
| 752 | to full name. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 753 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 754 | |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 755 | .. method:: findall(match, namespaces=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 756 | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 757 | Finds all matching subelements, by tag name or |
| 758 | :ref:`path <elementtree-xpath>`. Returns a list containing all matching |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 759 | elements in document order. *namespaces* is an optional mapping from |
| 760 | namespace prefix to full name. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 761 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 762 | |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 763 | .. method:: findtext(match, default=None, namespaces=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 764 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 765 | Finds text for the first subelement matching *match*. *match* may be |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 766 | a tag name or a :ref:`path <elementtree-xpath>`. Returns the text content |
| 767 | of the first matching element, or *default* if no element was found. |
| 768 | Note that if the matching element has no text content an empty string |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 769 | is returned. *namespaces* is an optional mapping from namespace prefix |
| 770 | to full name. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 771 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 772 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 773 | .. method:: getchildren() |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 774 | |
Serhiy Storchaka | 02ec92f | 2018-07-24 12:03:34 +0300 | [diff] [blame] | 775 | .. deprecated-removed:: 3.2 3.9 |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 776 | Use ``list(elem)`` or iteration. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 777 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 778 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 779 | .. method:: getiterator(tag=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 780 | |
Serhiy Storchaka | 02ec92f | 2018-07-24 12:03:34 +0300 | [diff] [blame] | 781 | .. deprecated-removed:: 3.2 3.9 |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 782 | Use method :meth:`Element.iter` instead. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 783 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 784 | |
Eli Bendersky | 396e8fc | 2012-03-23 14:24:20 +0200 | [diff] [blame] | 785 | .. method:: insert(index, subelement) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 786 | |
Eli Bendersky | 396e8fc | 2012-03-23 14:24:20 +0200 | [diff] [blame] | 787 | Inserts *subelement* at the given position in this element. Raises |
| 788 | :exc:`TypeError` if *subelement* is not an :class:`Element`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 789 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 790 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 791 | .. method:: iter(tag=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 792 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 793 | Creates a tree :term:`iterator` with the current element as the root. |
| 794 | The iterator iterates over this element and all elements below it, in |
| 795 | document (depth first) order. If *tag* is not ``None`` or ``'*'``, only |
| 796 | elements whose tag equals *tag* are returned from the iterator. If the |
| 797 | tree structure is modified during iteration, the result is undefined. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 798 | |
Ezio Melotti | 138fc89 | 2011-10-10 00:02:03 +0300 | [diff] [blame] | 799 | .. versionadded:: 3.2 |
| 800 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 801 | |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 802 | .. method:: iterfind(match, namespaces=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 803 | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 804 | Finds all matching subelements, by tag name or |
| 805 | :ref:`path <elementtree-xpath>`. Returns an iterable yielding all |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 806 | matching elements in document order. *namespaces* is an optional mapping |
| 807 | from namespace prefix to full name. |
| 808 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 809 | |
Ezio Melotti | f8754a6 | 2010-03-21 07:16:43 +0000 | [diff] [blame] | 810 | .. versionadded:: 3.2 |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 811 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 812 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 813 | .. method:: itertext() |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 814 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 815 | Creates a text iterator. The iterator loops over this element and all |
| 816 | subelements, in document order, and returns all inner text. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 817 | |
Ezio Melotti | f8754a6 | 2010-03-21 07:16:43 +0000 | [diff] [blame] | 818 | .. versionadded:: 3.2 |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 819 | |
| 820 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 821 | .. method:: makeelement(tag, attrib) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 822 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 823 | Creates a new element object of the same type as this element. Do not |
| 824 | call this method, use the :func:`SubElement` factory function instead. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 825 | |
| 826 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 827 | .. method:: remove(subelement) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 828 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 829 | Removes *subelement* from the element. Unlike the find\* methods this |
| 830 | method compares elements based on the instance identity, not on tag value |
| 831 | or contents. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 832 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 833 | :class:`Element` objects also support the following sequence type methods |
Serhiy Storchaka | 15e6590 | 2013-08-29 10:28:44 +0300 | [diff] [blame] | 834 | for working with subelements: :meth:`~object.__delitem__`, |
| 835 | :meth:`~object.__getitem__`, :meth:`~object.__setitem__`, |
| 836 | :meth:`~object.__len__`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 837 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 838 | Caution: Elements with no subelements will test as ``False``. This behavior |
| 839 | will change in future versions. Use specific ``len(elem)`` or ``elem is |
| 840 | None`` test instead. :: |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 841 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 842 | element = root.find('foo') |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 843 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 844 | if not element: # careful! |
| 845 | print("element not found, or element has no subelements") |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 846 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 847 | if element is None: |
| 848 | print("element not found") |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 849 | |
| 850 | |
| 851 | .. _elementtree-elementtree-objects: |
| 852 | |
| 853 | ElementTree Objects |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 854 | ^^^^^^^^^^^^^^^^^^^ |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 855 | |
| 856 | |
Georg Brandl | 7f01a13 | 2009-09-16 15:58:14 +0000 | [diff] [blame] | 857 | .. class:: ElementTree(element=None, file=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 858 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 859 | ElementTree wrapper class. This class represents an entire element |
| 860 | hierarchy, and adds some extra support for serialization to and from |
| 861 | standard XML. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 862 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 863 | *element* is the root element. The tree is initialized with the contents |
| 864 | of the XML *file* if given. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 865 | |
| 866 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 867 | .. method:: _setroot(element) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 868 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 869 | Replaces the root element for this tree. This discards the current |
| 870 | contents of the tree, and replaces it with the given element. Use with |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 871 | care. *element* is an element instance. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 872 | |
| 873 | |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 874 | .. method:: find(match, namespaces=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 875 | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 876 | Same as :meth:`Element.find`, starting at the root of the tree. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 877 | |
| 878 | |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 879 | .. method:: findall(match, namespaces=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 880 | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 881 | Same as :meth:`Element.findall`, starting at the root of the tree. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 882 | |
| 883 | |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 884 | .. method:: findtext(match, default=None, namespaces=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 885 | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 886 | Same as :meth:`Element.findtext`, starting at the root of the tree. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 887 | |
| 888 | |
Georg Brandl | 7f01a13 | 2009-09-16 15:58:14 +0000 | [diff] [blame] | 889 | .. method:: getiterator(tag=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 890 | |
Serhiy Storchaka | 02ec92f | 2018-07-24 12:03:34 +0300 | [diff] [blame] | 891 | .. deprecated-removed:: 3.2 3.9 |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 892 | Use method :meth:`ElementTree.iter` instead. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 893 | |
| 894 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 895 | .. method:: getroot() |
Florent Xicluna | c17f172 | 2010-08-08 19:48:29 +0000 | [diff] [blame] | 896 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 897 | Returns the root element for this tree. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 898 | |
| 899 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 900 | .. method:: iter(tag=None) |
| 901 | |
| 902 | Creates and returns a tree iterator for the root element. The iterator |
| 903 | loops over all elements in this tree, in section order. *tag* is the tag |
Martin Panter | d21e0b5 | 2015-10-10 10:36:22 +0000 | [diff] [blame] | 904 | to look for (default is to return all elements). |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 905 | |
| 906 | |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 907 | .. method:: iterfind(match, namespaces=None) |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 908 | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 909 | Same as :meth:`Element.iterfind`, starting at the root of the tree. |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 910 | |
Ezio Melotti | f8754a6 | 2010-03-21 07:16:43 +0000 | [diff] [blame] | 911 | .. versionadded:: 3.2 |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 912 | |
| 913 | |
Georg Brandl | 7f01a13 | 2009-09-16 15:58:14 +0000 | [diff] [blame] | 914 | .. method:: parse(source, parser=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 915 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 916 | Loads an external XML section into this element tree. *source* is a file |
Antoine Pitrou | 11cb961 | 2010-09-15 11:11:28 +0000 | [diff] [blame] | 917 | name or :term:`file object`. *parser* is an optional parser instance. |
Eli Bendersky | 52467b1 | 2012-06-01 07:13:08 +0300 | [diff] [blame] | 918 | If not given, the standard :class:`XMLParser` parser is used. Returns the |
| 919 | section root element. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 920 | |
| 921 | |
Eli Bendersky | f96cf91 | 2012-07-15 06:19:44 +0300 | [diff] [blame] | 922 | .. method:: write(file, encoding="us-ascii", xml_declaration=None, \ |
Serhiy Storchaka | 9e189f0 | 2013-01-13 22:24:27 +0200 | [diff] [blame] | 923 | default_namespace=None, method="xml", *, \ |
Eli Bendersky | e9af827 | 2013-01-13 06:27:51 -0800 | [diff] [blame] | 924 | short_empty_elements=True) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 925 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 926 | Writes the element tree to a file, as XML. *file* is a file name, or a |
Eli Bendersky | f96cf91 | 2012-07-15 06:19:44 +0300 | [diff] [blame] | 927 | :term:`file object` opened for writing. *encoding* [1]_ is the output |
| 928 | encoding (default is US-ASCII). |
| 929 | *xml_declaration* controls if an XML declaration should be added to the |
| 930 | file. Use ``False`` for never, ``True`` for always, ``None`` |
| 931 | for only if not US-ASCII or UTF-8 or Unicode (default is ``None``). |
Serhiy Storchaka | 03530b9 | 2013-01-13 21:58:04 +0200 | [diff] [blame] | 932 | *default_namespace* sets the default XML namespace (for "xmlns"). |
Eli Bendersky | f96cf91 | 2012-07-15 06:19:44 +0300 | [diff] [blame] | 933 | *method* is either ``"xml"``, ``"html"`` or ``"text"`` (default is |
| 934 | ``"xml"``). |
Eli Bendersky | a9a2ef5 | 2013-01-13 06:04:43 -0800 | [diff] [blame] | 935 | The keyword-only *short_empty_elements* parameter controls the formatting |
Serhiy Storchaka | a97cd2e | 2016-10-19 16:43:42 +0300 | [diff] [blame] | 936 | of elements that contain no content. If ``True`` (the default), they are |
Eli Bendersky | a9a2ef5 | 2013-01-13 06:04:43 -0800 | [diff] [blame] | 937 | emitted as a single self-closed tag, otherwise they are emitted as a pair |
| 938 | of start/end tags. |
Eli Bendersky | f96cf91 | 2012-07-15 06:19:44 +0300 | [diff] [blame] | 939 | |
| 940 | The output is either a string (:class:`str`) or binary (:class:`bytes`). |
| 941 | This is controlled by the *encoding* argument. If *encoding* is |
| 942 | ``"unicode"``, the output is a string; otherwise, it's binary. Note that |
| 943 | this may conflict with the type of *file* if it's an open |
| 944 | :term:`file object`; make sure you do not try to write a string to a |
| 945 | binary stream and vice versa. |
| 946 | |
R David Murray | 575fb31 | 2013-12-25 23:21:03 -0500 | [diff] [blame] | 947 | .. versionadded:: 3.4 |
| 948 | The *short_empty_elements* parameter. |
Eli Bendersky | a9a2ef5 | 2013-01-13 06:04:43 -0800 | [diff] [blame] | 949 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 950 | |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 951 | This is the XML file that is going to be manipulated:: |
| 952 | |
| 953 | <html> |
| 954 | <head> |
| 955 | <title>Example page</title> |
| 956 | </head> |
| 957 | <body> |
Georg Brandl | 48310cd | 2009-01-03 21:18:54 +0000 | [diff] [blame] | 958 | <p>Moved to <a href="http://example.org/">example.org</a> |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 959 | or <a href="http://example.com/">example.com</a>.</p> |
| 960 | </body> |
| 961 | </html> |
| 962 | |
| 963 | Example of changing the attribute "target" of every link in first paragraph:: |
| 964 | |
| 965 | >>> from xml.etree.ElementTree import ElementTree |
| 966 | >>> tree = ElementTree() |
| 967 | >>> tree.parse("index.xhtml") |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 968 | <Element 'html' at 0xb77e6fac> |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 969 | >>> p = tree.find("body/p") # Finds first occurrence of tag p in body |
| 970 | >>> p |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 971 | <Element 'p' at 0xb77ec26c> |
| 972 | >>> links = list(p.iter("a")) # Returns list of all links |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 973 | >>> links |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 974 | [<Element 'a' at 0xb77ec2ac>, <Element 'a' at 0xb77ec1cc>] |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 975 | >>> for i in links: # Iterates through all found links |
| 976 | ... i.attrib["target"] = "blank" |
| 977 | >>> tree.write("output.xhtml") |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 978 | |
| 979 | .. _elementtree-qname-objects: |
| 980 | |
| 981 | QName Objects |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 982 | ^^^^^^^^^^^^^ |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 983 | |
| 984 | |
Georg Brandl | 7f01a13 | 2009-09-16 15:58:14 +0000 | [diff] [blame] | 985 | .. class:: QName(text_or_uri, tag=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 986 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 987 | QName wrapper. This can be used to wrap a QName attribute value, in order |
| 988 | to get proper namespace handling on output. *text_or_uri* is a string |
| 989 | containing the QName value, in the form {uri}local, or, if the tag argument |
| 990 | is given, the URI part of a QName. If *tag* is given, the first argument is |
Martin Panter | 6245cb3 | 2016-04-15 02:14:19 +0000 | [diff] [blame] | 991 | interpreted as a URI, and this argument is interpreted as a local name. |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 992 | :class:`QName` instances are opaque. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 993 | |
| 994 | |
Antoine Pitrou | 5b235d0 | 2013-04-18 19:37:06 +0200 | [diff] [blame] | 995 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 996 | .. _elementtree-treebuilder-objects: |
| 997 | |
| 998 | TreeBuilder Objects |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 999 | ^^^^^^^^^^^^^^^^^^^ |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1000 | |
| 1001 | |
Georg Brandl | 7f01a13 | 2009-09-16 15:58:14 +0000 | [diff] [blame] | 1002 | .. class:: TreeBuilder(element_factory=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1003 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 1004 | Generic element structure builder. This builder converts a sequence of |
| 1005 | start, data, and end method calls to a well-formed element structure. You |
| 1006 | can use this class to build an element structure using a custom XML parser, |
Eli Bendersky | 48d358b | 2012-05-30 17:57:50 +0300 | [diff] [blame] | 1007 | or a parser for some other XML-like format. *element_factory*, when given, |
| 1008 | must be a callable accepting two positional arguments: a tag and |
| 1009 | a dict of attributes. It is expected to return a new element instance. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1010 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 1011 | .. method:: close() |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1012 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 1013 | Flushes the builder buffers, and returns the toplevel document |
| 1014 | element. Returns an :class:`Element` instance. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1015 | |
| 1016 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 1017 | .. method:: data(data) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1018 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 1019 | Adds text to the current element. *data* is a string. This should be |
| 1020 | either a bytestring, or a Unicode string. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1021 | |
| 1022 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 1023 | .. method:: end(tag) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1024 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 1025 | Closes the current element. *tag* is the element name. Returns the |
| 1026 | closed element. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1027 | |
| 1028 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 1029 | .. method:: start(tag, attrs) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1030 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 1031 | Opens a new element. *tag* is the element name. *attrs* is a dictionary |
| 1032 | containing element attributes. Returns the opened element. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1033 | |
| 1034 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 1035 | In addition, a custom :class:`TreeBuilder` object can provide the |
| 1036 | following method: |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1037 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 1038 | .. method:: doctype(name, pubid, system) |
| 1039 | |
| 1040 | Handles a doctype declaration. *name* is the doctype name. *pubid* is |
| 1041 | the public identifier. *system* is the system identifier. This method |
| 1042 | does not exist on the default :class:`TreeBuilder` class. |
| 1043 | |
Ezio Melotti | f8754a6 | 2010-03-21 07:16:43 +0000 | [diff] [blame] | 1044 | .. versionadded:: 3.2 |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1045 | |
| 1046 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 1047 | .. _elementtree-xmlparser-objects: |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1048 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 1049 | XMLParser Objects |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 1050 | ^^^^^^^^^^^^^^^^^ |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 1051 | |
| 1052 | |
Serhiy Storchaka | 02ec92f | 2018-07-24 12:03:34 +0300 | [diff] [blame] | 1053 | .. class:: XMLParser(*, target=None, encoding=None) |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 1054 | |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 1055 | This class is the low-level building block of the module. It uses |
| 1056 | :mod:`xml.parsers.expat` for efficient, event-based parsing of XML. It can |
Georg Brandl | adeffcc | 2016-02-26 19:13:47 +0100 | [diff] [blame] | 1057 | be fed XML data incrementally with the :meth:`feed` method, and parsing |
| 1058 | events are translated to a push API - by invoking callbacks on the *target* |
| 1059 | object. If *target* is omitted, the standard :class:`TreeBuilder` is used. |
Serhiy Storchaka | 02ec92f | 2018-07-24 12:03:34 +0300 | [diff] [blame] | 1060 | If *encoding* [1]_ is given, the value overrides the |
Georg Brandl | adeffcc | 2016-02-26 19:13:47 +0100 | [diff] [blame] | 1061 | encoding specified in the XML file. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1062 | |
Serhiy Storchaka | 02ec92f | 2018-07-24 12:03:34 +0300 | [diff] [blame] | 1063 | .. versionchanged:: 3.8 |
| 1064 | Parameters are now :ref:`keyword-only <keyword-only_parameter>`. |
| 1065 | The *html* argument no longer supported. |
| 1066 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1067 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 1068 | .. method:: close() |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1069 | |
Eli Bendersky | bfd7837 | 2013-08-24 15:11:44 -0700 | [diff] [blame] | 1070 | Finishes feeding data to the parser. Returns the result of calling the |
Eli Bendersky | bf8ab77 | 2013-08-25 15:27:36 -0700 | [diff] [blame] | 1071 | ``close()`` method of the *target* passed during construction; by default, |
| 1072 | this is the toplevel document element. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1073 | |
| 1074 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 1075 | .. method:: feed(data) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1076 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 1077 | Feeds data to the parser. *data* is encoded data. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1078 | |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 1079 | :meth:`XMLParser.feed` calls *target*\'s ``start(tag, attrs_dict)`` method |
| 1080 | for each opening tag, its ``end(tag)`` method for each closing tag, and data |
| 1081 | is processed by method ``data(data)``. :meth:`XMLParser.close` calls |
| 1082 | *target*\'s method ``close()``. :class:`XMLParser` can be used not only for |
| 1083 | building a tree structure. This is an example of counting the maximum depth |
| 1084 | of an XML file:: |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 1085 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 1086 | >>> from xml.etree.ElementTree import XMLParser |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 1087 | >>> class MaxDepth: # The target object of the parser |
| 1088 | ... maxDepth = 0 |
| 1089 | ... depth = 0 |
| 1090 | ... def start(self, tag, attrib): # Called for each opening tag. |
Georg Brandl | 48310cd | 2009-01-03 21:18:54 +0000 | [diff] [blame] | 1091 | ... self.depth += 1 |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 1092 | ... if self.depth > self.maxDepth: |
| 1093 | ... self.maxDepth = self.depth |
| 1094 | ... def end(self, tag): # Called for each closing tag. |
| 1095 | ... self.depth -= 1 |
Georg Brandl | 48310cd | 2009-01-03 21:18:54 +0000 | [diff] [blame] | 1096 | ... def data(self, data): |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 1097 | ... pass # We do not need to do anything with data. |
| 1098 | ... def close(self): # Called when all data has been parsed. |
| 1099 | ... return self.maxDepth |
Georg Brandl | 48310cd | 2009-01-03 21:18:54 +0000 | [diff] [blame] | 1100 | ... |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 1101 | >>> target = MaxDepth() |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 1102 | >>> parser = XMLParser(target=target) |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 1103 | >>> exampleXml = """ |
| 1104 | ... <a> |
| 1105 | ... <b> |
| 1106 | ... </b> |
| 1107 | ... <b> |
| 1108 | ... <c> |
| 1109 | ... <d> |
| 1110 | ... </d> |
| 1111 | ... </c> |
| 1112 | ... </b> |
| 1113 | ... </a>""" |
| 1114 | >>> parser.feed(exampleXml) |
| 1115 | >>> parser.close() |
| 1116 | 4 |
Christian Heimes | b186d00 | 2008-03-18 15:15:01 +0000 | [diff] [blame] | 1117 | |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 1118 | |
| 1119 | .. _elementtree-xmlpullparser-objects: |
| 1120 | |
| 1121 | XMLPullParser Objects |
| 1122 | ^^^^^^^^^^^^^^^^^^^^^ |
| 1123 | |
| 1124 | .. class:: XMLPullParser(events=None) |
| 1125 | |
Eli Bendersky | 2c68e30 | 2013-08-31 07:37:23 -0700 | [diff] [blame] | 1126 | A pull parser suitable for non-blocking applications. Its input-side API is |
| 1127 | similar to that of :class:`XMLParser`, but instead of pushing calls to a |
| 1128 | callback target, :class:`XMLPullParser` collects an internal list of parsing |
| 1129 | events and lets the user read from it. *events* is a sequence of events to |
| 1130 | report back. The supported events are the strings ``"start"``, ``"end"``, |
| 1131 | ``"start-ns"`` and ``"end-ns"`` (the "ns" events are used to get detailed |
| 1132 | namespace information). If *events* is omitted, only ``"end"`` events are |
| 1133 | reported. |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 1134 | |
| 1135 | .. method:: feed(data) |
| 1136 | |
| 1137 | Feed the given bytes data to the parser. |
| 1138 | |
| 1139 | .. method:: close() |
| 1140 | |
Nick Coghlan | 4cc2afa | 2013-09-28 23:50:35 +1000 | [diff] [blame] | 1141 | Signal the parser that the data stream is terminated. Unlike |
| 1142 | :meth:`XMLParser.close`, this method always returns :const:`None`. |
| 1143 | Any events not yet retrieved when the parser is closed can still be |
| 1144 | read with :meth:`read_events`. |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 1145 | |
| 1146 | .. method:: read_events() |
| 1147 | |
R David Murray | 410d320 | 2014-01-04 23:52:50 -0500 | [diff] [blame] | 1148 | Return an iterator over the events which have been encountered in the |
| 1149 | data fed to the |
| 1150 | parser. The iterator yields ``(event, elem)`` pairs, where *event* is a |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 1151 | string representing the type of event (e.g. ``"end"``) and *elem* is the |
Nick Coghlan | 4cc2afa | 2013-09-28 23:50:35 +1000 | [diff] [blame] | 1152 | encountered :class:`Element` object. |
| 1153 | |
| 1154 | Events provided in a previous call to :meth:`read_events` will not be |
R David Murray | 410d320 | 2014-01-04 23:52:50 -0500 | [diff] [blame] | 1155 | yielded again. Events are consumed from the internal queue only when |
| 1156 | they are retrieved from the iterator, so multiple readers iterating in |
| 1157 | parallel over iterators obtained from :meth:`read_events` will have |
| 1158 | unpredictable results. |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 1159 | |
| 1160 | .. note:: |
| 1161 | |
| 1162 | :class:`XMLPullParser` only guarantees that it has seen the ">" |
| 1163 | character of a starting tag when it emits a "start" event, so the |
| 1164 | attributes are defined, but the contents of the text and tail attributes |
| 1165 | are undefined at that point. The same applies to the element children; |
| 1166 | they may or may not be present. |
| 1167 | |
| 1168 | If you need a fully populated element, look for "end" events instead. |
| 1169 | |
| 1170 | .. versionadded:: 3.4 |
| 1171 | |
Eli Bendersky | 5b77d81 | 2012-03-16 08:20:05 +0200 | [diff] [blame] | 1172 | Exceptions |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 1173 | ^^^^^^^^^^ |
Eli Bendersky | 5b77d81 | 2012-03-16 08:20:05 +0200 | [diff] [blame] | 1174 | |
| 1175 | .. class:: ParseError |
| 1176 | |
| 1177 | XML parse error, raised by the various parsing methods in this module when |
| 1178 | parsing fails. The string representation of an instance of this exception |
| 1179 | will contain a user-friendly error message. In addition, it will have |
| 1180 | the following attributes available: |
| 1181 | |
| 1182 | .. attribute:: code |
| 1183 | |
| 1184 | A numeric error code from the expat parser. See the documentation of |
| 1185 | :mod:`xml.parsers.expat` for the list of error codes and their meanings. |
| 1186 | |
| 1187 | .. attribute:: position |
| 1188 | |
| 1189 | A tuple of *line*, *column* numbers, specifying where the error occurred. |
Christian Heimes | b186d00 | 2008-03-18 15:15:01 +0000 | [diff] [blame] | 1190 | |
| 1191 | .. rubric:: Footnotes |
| 1192 | |
Serhiy Storchaka | d97b7dc | 2017-05-16 23:18:09 +0300 | [diff] [blame] | 1193 | .. [1] The encoding string included in XML output should conform to the |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 1194 | appropriate standards. For example, "UTF-8" is valid, but "UTF8" is |
Serhiy Storchaka | 6dff020 | 2016-05-07 10:49:07 +0300 | [diff] [blame] | 1195 | not. See https://www.w3.org/TR/2006/REC-xml11-20060816/#NT-EncodingDecl |
| 1196 | and https://www.iana.org/assignments/character-sets/character-sets.xhtml. |