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. |
| 6 | .. moduleauthor:: Fredrik Lundh <fredrik@pythonware.com> |
| 7 | |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 8 | The :mod:`xml.etree.ElementTree` module implements a simple and efficient API |
| 9 | for parsing and creating XML data. |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 10 | |
Florent Xicluna | a72a98f | 2012-02-13 11:03:30 +0100 | [diff] [blame] | 11 | .. versionchanged:: 3.3 |
| 12 | This module will use a fast implementation whenever available. |
| 13 | The :mod:`xml.etree.cElementTree` module is deprecated. |
| 14 | |
Christian Heimes | 7380a67 | 2013-03-26 17:35:55 +0100 | [diff] [blame] | 15 | |
| 16 | .. warning:: |
| 17 | |
| 18 | The :mod:`xml.etree.ElementTree` module is not secure against |
| 19 | maliciously constructed data. If you need to parse untrusted or |
| 20 | unauthenticated data see :ref:`xml-vulnerabilities`. |
| 21 | |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 22 | Tutorial |
| 23 | -------- |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 24 | |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 25 | This is a short tutorial for using :mod:`xml.etree.ElementTree` (``ET`` in |
| 26 | short). The goal is to demonstrate some of the building blocks and basic |
| 27 | concepts of the module. |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 28 | |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 29 | XML tree and elements |
| 30 | ^^^^^^^^^^^^^^^^^^^^^ |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 31 | |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 32 | XML is an inherently hierarchical data format, and the most natural way to |
| 33 | represent it is with a tree. ``ET`` has two classes for this purpose - |
| 34 | :class:`ElementTree` represents the whole XML document as a tree, and |
| 35 | :class:`Element` represents a single node in this tree. Interactions with |
| 36 | the whole document (reading and writing to/from files) are usually done |
| 37 | on the :class:`ElementTree` level. Interactions with a single XML element |
| 38 | and its sub-elements are done on the :class:`Element` level. |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 39 | |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 40 | .. _elementtree-parsing-xml: |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 41 | |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 42 | Parsing XML |
| 43 | ^^^^^^^^^^^ |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 44 | |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 45 | 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] | 46 | |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 47 | .. code-block:: xml |
| 48 | |
| 49 | <?xml version="1.0"?> |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 50 | <data> |
Eli Bendersky | 3115f0d | 2012-08-15 14:26:30 +0300 | [diff] [blame] | 51 | <country name="Liechtenstein"> |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 52 | <rank>1</rank> |
| 53 | <year>2008</year> |
| 54 | <gdppc>141100</gdppc> |
| 55 | <neighbor name="Austria" direction="E"/> |
| 56 | <neighbor name="Switzerland" direction="W"/> |
| 57 | </country> |
| 58 | <country name="Singapore"> |
| 59 | <rank>4</rank> |
| 60 | <year>2011</year> |
| 61 | <gdppc>59900</gdppc> |
| 62 | <neighbor name="Malaysia" direction="N"/> |
| 63 | </country> |
| 64 | <country name="Panama"> |
| 65 | <rank>68</rank> |
| 66 | <year>2011</year> |
| 67 | <gdppc>13600</gdppc> |
| 68 | <neighbor name="Costa Rica" direction="W"/> |
| 69 | <neighbor name="Colombia" direction="E"/> |
| 70 | </country> |
| 71 | </data> |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 72 | |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 73 | We can import this data by reading from a file:: |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 74 | |
| 75 | import xml.etree.ElementTree as ET |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 76 | tree = ET.parse('country_data.xml') |
| 77 | root = tree.getroot() |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 78 | |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 79 | Or directly from a string:: |
| 80 | |
| 81 | root = ET.fromstring(country_data_as_string) |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 82 | |
| 83 | :func:`fromstring` parses XML from a string directly into an :class:`Element`, |
| 84 | 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] | 85 | create an :class:`ElementTree`. Check the documentation to be sure. |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 86 | |
| 87 | As an :class:`Element`, ``root`` has a tag and a dictionary of attributes:: |
| 88 | |
| 89 | >>> root.tag |
| 90 | 'data' |
| 91 | >>> root.attrib |
| 92 | {} |
| 93 | |
| 94 | It also has children nodes over which we can iterate:: |
| 95 | |
| 96 | >>> for child in root: |
| 97 | ... print(child.tag, child.attrib) |
| 98 | ... |
Eli Bendersky | 3115f0d | 2012-08-15 14:26:30 +0300 | [diff] [blame] | 99 | country {'name': 'Liechtenstein'} |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 100 | country {'name': 'Singapore'} |
| 101 | country {'name': 'Panama'} |
| 102 | |
| 103 | Children are nested, and we can access specific child nodes by index:: |
| 104 | |
| 105 | >>> root[0][1].text |
| 106 | '2008' |
| 107 | |
R David Murray | 410d320 | 2014-01-04 23:52:50 -0500 | [diff] [blame] | 108 | |
Eli Bendersky | 0bd22d4 | 2014-04-03 06:14:38 -0700 | [diff] [blame] | 109 | .. note:: |
| 110 | |
| 111 | Not all elements of the XML input will end up as elements of the |
| 112 | parsed tree. Currently, this module skips over any XML comments, |
| 113 | processing instructions, and document type declarations in the |
| 114 | input. Nevertheless, trees built using this module's API rather |
| 115 | than parsing from XML text can have comments and processing |
| 116 | instructions in them; they will be included when generating XML |
| 117 | output. A document type declaration may be accessed by passing a |
| 118 | custom :class:`TreeBuilder` instance to the :class:`XMLParser` |
| 119 | constructor. |
| 120 | |
| 121 | |
R David Murray | 410d320 | 2014-01-04 23:52:50 -0500 | [diff] [blame] | 122 | .. _elementtree-pull-parsing: |
| 123 | |
Eli Bendersky | 2c68e30 | 2013-08-31 07:37:23 -0700 | [diff] [blame] | 124 | Pull API for non-blocking parsing |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 125 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ |
Eli Bendersky | 3bdead1 | 2013-04-20 09:06:27 -0700 | [diff] [blame] | 126 | |
R David Murray | 410d320 | 2014-01-04 23:52:50 -0500 | [diff] [blame] | 127 | Most parsing functions provided by this module require the whole document |
| 128 | to be read at once before returning any result. It is possible to use an |
| 129 | :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] | 130 | calls methods on a callback target, which is too low-level and inconvenient for |
| 131 | most needs. Sometimes what the user really wants is to be able to parse XML |
| 132 | incrementally, without blocking operations, while enjoying the convenience of |
| 133 | fully constructed :class:`Element` objects. |
Eli Bendersky | 3bdead1 | 2013-04-20 09:06:27 -0700 | [diff] [blame] | 134 | |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 135 | The most powerful tool for doing this is :class:`XMLPullParser`. It does not |
| 136 | require a blocking read to obtain the XML data, and is instead fed with data |
| 137 | incrementally with :meth:`XMLPullParser.feed` calls. To get the parsed XML |
R David Murray | 410d320 | 2014-01-04 23:52:50 -0500 | [diff] [blame] | 138 | elements, call :meth:`XMLPullParser.read_events`. Here is an example:: |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 139 | |
Eli Bendersky | 2c68e30 | 2013-08-31 07:37:23 -0700 | [diff] [blame] | 140 | >>> parser = ET.XMLPullParser(['start', 'end']) |
| 141 | >>> parser.feed('<mytag>sometext') |
| 142 | >>> list(parser.read_events()) |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 143 | [('start', <Element 'mytag' at 0x7fa66db2be58>)] |
Eli Bendersky | 2c68e30 | 2013-08-31 07:37:23 -0700 | [diff] [blame] | 144 | >>> parser.feed(' more text</mytag>') |
| 145 | >>> for event, elem in parser.read_events(): |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 146 | ... print(event) |
| 147 | ... print(elem.tag, 'text=', elem.text) |
| 148 | ... |
| 149 | end |
Eli Bendersky | 3bdead1 | 2013-04-20 09:06:27 -0700 | [diff] [blame] | 150 | |
Eli Bendersky | 2c68e30 | 2013-08-31 07:37:23 -0700 | [diff] [blame] | 151 | 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] | 152 | where the XML data is being received from a socket or read incrementally from |
| 153 | some storage device. In such cases, blocking reads are unacceptable. |
| 154 | |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 155 | Because it's so flexible, :class:`XMLPullParser` can be inconvenient to use for |
| 156 | simpler use-cases. If you don't mind your application blocking on reading XML |
| 157 | data but would still like to have incremental parsing capabilities, take a look |
| 158 | at :func:`iterparse`. It can be useful when you're reading a large XML document |
| 159 | and don't want to hold it wholly in memory. |
Eli Bendersky | 3bdead1 | 2013-04-20 09:06:27 -0700 | [diff] [blame] | 160 | |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 161 | Finding interesting elements |
| 162 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ |
| 163 | |
| 164 | :class:`Element` has some useful methods that help iterate recursively over all |
| 165 | the sub-tree below it (its children, their children, and so on). For example, |
| 166 | :meth:`Element.iter`:: |
| 167 | |
| 168 | >>> for neighbor in root.iter('neighbor'): |
| 169 | ... print(neighbor.attrib) |
| 170 | ... |
| 171 | {'name': 'Austria', 'direction': 'E'} |
| 172 | {'name': 'Switzerland', 'direction': 'W'} |
| 173 | {'name': 'Malaysia', 'direction': 'N'} |
| 174 | {'name': 'Costa Rica', 'direction': 'W'} |
| 175 | {'name': 'Colombia', 'direction': 'E'} |
| 176 | |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 177 | :meth:`Element.findall` finds only elements with a tag which are direct |
| 178 | children of the current element. :meth:`Element.find` finds the *first* child |
Georg Brandl | bdaee3a | 2013-10-06 09:23:03 +0200 | [diff] [blame] | 179 | 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] | 180 | content. :meth:`Element.get` accesses the element's attributes:: |
| 181 | |
| 182 | >>> for country in root.findall('country'): |
| 183 | ... rank = country.find('rank').text |
| 184 | ... name = country.get('name') |
| 185 | ... print(name, rank) |
| 186 | ... |
Eli Bendersky | 3115f0d | 2012-08-15 14:26:30 +0300 | [diff] [blame] | 187 | Liechtenstein 1 |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 188 | Singapore 4 |
| 189 | Panama 68 |
| 190 | |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 191 | More sophisticated specification of which elements to look for is possible by |
| 192 | using :ref:`XPath <elementtree-xpath>`. |
| 193 | |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 194 | Modifying an XML File |
| 195 | ^^^^^^^^^^^^^^^^^^^^^ |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 196 | |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 197 | :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] | 198 | The :meth:`ElementTree.write` method serves this purpose. |
| 199 | |
| 200 | Once created, an :class:`Element` object may be manipulated by directly changing |
| 201 | its fields (such as :attr:`Element.text`), adding and modifying attributes |
| 202 | (:meth:`Element.set` method), as well as adding new children (for example |
| 203 | with :meth:`Element.append`). |
| 204 | |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 205 | Let's say we want to add one to each country's rank, and add an ``updated`` |
| 206 | attribute to the rank element:: |
| 207 | |
| 208 | >>> for rank in root.iter('rank'): |
| 209 | ... new_rank = int(rank.text) + 1 |
| 210 | ... rank.text = str(new_rank) |
| 211 | ... rank.set('updated', 'yes') |
| 212 | ... |
Eli Bendersky | a1b0f6d | 2012-08-18 05:42:22 +0300 | [diff] [blame] | 213 | >>> tree.write('output.xml') |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 214 | |
| 215 | Our XML now looks like this: |
| 216 | |
| 217 | .. code-block:: xml |
| 218 | |
| 219 | <?xml version="1.0"?> |
| 220 | <data> |
Eli Bendersky | 3115f0d | 2012-08-15 14:26:30 +0300 | [diff] [blame] | 221 | <country name="Liechtenstein"> |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 222 | <rank updated="yes">2</rank> |
| 223 | <year>2008</year> |
| 224 | <gdppc>141100</gdppc> |
| 225 | <neighbor name="Austria" direction="E"/> |
| 226 | <neighbor name="Switzerland" direction="W"/> |
| 227 | </country> |
| 228 | <country name="Singapore"> |
| 229 | <rank updated="yes">5</rank> |
| 230 | <year>2011</year> |
| 231 | <gdppc>59900</gdppc> |
| 232 | <neighbor name="Malaysia" direction="N"/> |
| 233 | </country> |
| 234 | <country name="Panama"> |
| 235 | <rank updated="yes">69</rank> |
| 236 | <year>2011</year> |
| 237 | <gdppc>13600</gdppc> |
| 238 | <neighbor name="Costa Rica" direction="W"/> |
| 239 | <neighbor name="Colombia" direction="E"/> |
| 240 | </country> |
| 241 | </data> |
| 242 | |
| 243 | We can remove elements using :meth:`Element.remove`. Let's say we want to |
| 244 | remove all countries with a rank higher than 50:: |
| 245 | |
| 246 | >>> for country in root.findall('country'): |
| 247 | ... rank = int(country.find('rank').text) |
| 248 | ... if rank > 50: |
| 249 | ... root.remove(country) |
| 250 | ... |
Eli Bendersky | a1b0f6d | 2012-08-18 05:42:22 +0300 | [diff] [blame] | 251 | >>> tree.write('output.xml') |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 252 | |
| 253 | Our XML now looks like this: |
| 254 | |
| 255 | .. code-block:: xml |
| 256 | |
| 257 | <?xml version="1.0"?> |
| 258 | <data> |
Eli Bendersky | 3115f0d | 2012-08-15 14:26:30 +0300 | [diff] [blame] | 259 | <country name="Liechtenstein"> |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 260 | <rank updated="yes">2</rank> |
| 261 | <year>2008</year> |
| 262 | <gdppc>141100</gdppc> |
| 263 | <neighbor name="Austria" direction="E"/> |
| 264 | <neighbor name="Switzerland" direction="W"/> |
| 265 | </country> |
| 266 | <country name="Singapore"> |
| 267 | <rank updated="yes">5</rank> |
| 268 | <year>2011</year> |
| 269 | <gdppc>59900</gdppc> |
| 270 | <neighbor name="Malaysia" direction="N"/> |
| 271 | </country> |
| 272 | </data> |
| 273 | |
| 274 | Building XML documents |
| 275 | ^^^^^^^^^^^^^^^^^^^^^^ |
| 276 | |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 277 | The :func:`SubElement` function also provides a convenient way to create new |
| 278 | sub-elements for a given element:: |
| 279 | |
| 280 | >>> a = ET.Element('a') |
| 281 | >>> b = ET.SubElement(a, 'b') |
| 282 | >>> c = ET.SubElement(a, 'c') |
| 283 | >>> d = ET.SubElement(c, 'd') |
| 284 | >>> ET.dump(a) |
| 285 | <a><b /><c><d /></c></a> |
| 286 | |
| 287 | Additional resources |
| 288 | ^^^^^^^^^^^^^^^^^^^^ |
| 289 | |
| 290 | See http://effbot.org/zone/element-index.htm for tutorials and links to other |
| 291 | docs. |
| 292 | |
| 293 | |
| 294 | .. _elementtree-xpath: |
| 295 | |
| 296 | XPath support |
| 297 | ------------- |
| 298 | |
| 299 | This module provides limited support for |
| 300 | `XPath expressions <http://www.w3.org/TR/xpath>`_ for locating elements in a |
| 301 | tree. The goal is to support a small subset of the abbreviated syntax; a full |
| 302 | XPath engine is outside the scope of the module. |
| 303 | |
| 304 | Example |
| 305 | ^^^^^^^ |
| 306 | |
| 307 | Here's an example that demonstrates some of the XPath capabilities of the |
| 308 | module. We'll be using the ``countrydata`` XML document from the |
| 309 | :ref:`Parsing XML <elementtree-parsing-xml>` section:: |
| 310 | |
| 311 | import xml.etree.ElementTree as ET |
| 312 | |
| 313 | root = ET.fromstring(countrydata) |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 314 | |
| 315 | # Top-level elements |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 316 | root.findall(".") |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 317 | |
| 318 | # All 'neighbor' grand-children of 'country' children of the top-level |
| 319 | # elements |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 320 | root.findall("./country/neighbor") |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 321 | |
| 322 | # Nodes with name='Singapore' that have a 'year' child |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 323 | root.findall(".//year/..[@name='Singapore']") |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 324 | |
| 325 | # 'year' nodes that are children of nodes with name='Singapore' |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 326 | root.findall(".//*[@name='Singapore']/year") |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 327 | |
| 328 | # All 'neighbor' nodes that are the second child of their parent |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 329 | root.findall(".//neighbor[2]") |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 330 | |
| 331 | Supported XPath syntax |
| 332 | ^^^^^^^^^^^^^^^^^^^^^^ |
| 333 | |
Georg Brandl | 44ea77b | 2013-03-28 13:28:44 +0100 | [diff] [blame] | 334 | .. tabularcolumns:: |l|L| |
| 335 | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 336 | +-----------------------+------------------------------------------------------+ |
| 337 | | Syntax | Meaning | |
| 338 | +=======================+======================================================+ |
| 339 | | ``tag`` | Selects all child elements with the given tag. | |
| 340 | | | For example, ``spam`` selects all child elements | |
Raymond Hettinger | 1e1e601 | 2014-03-29 11:50:08 -0700 | [diff] [blame] | 341 | | | named ``spam``, and ``spam/egg`` selects all | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 342 | | | grandchildren named ``egg`` in all children named | |
| 343 | | | ``spam``. | |
| 344 | +-----------------------+------------------------------------------------------+ |
| 345 | | ``*`` | Selects all child elements. For example, ``*/egg`` | |
| 346 | | | selects all grandchildren named ``egg``. | |
| 347 | +-----------------------+------------------------------------------------------+ |
| 348 | | ``.`` | Selects the current node. This is mostly useful | |
| 349 | | | at the beginning of the path, to indicate that it's | |
| 350 | | | a relative path. | |
| 351 | +-----------------------+------------------------------------------------------+ |
| 352 | | ``//`` | Selects all subelements, on all levels beneath the | |
Eli Bendersky | ede001a | 2012-03-27 04:57:23 +0200 | [diff] [blame] | 353 | | | current element. For example, ``.//egg`` selects | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 354 | | | all ``egg`` elements in the entire tree. | |
| 355 | +-----------------------+------------------------------------------------------+ |
Eli Bendersky | 323a43a | 2012-10-09 06:46:33 -0700 | [diff] [blame] | 356 | | ``..`` | Selects the parent element. Returns ``None`` if the | |
| 357 | | | path attempts to reach the ancestors of the start | |
| 358 | | | element (the element ``find`` was called on). | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 359 | +-----------------------+------------------------------------------------------+ |
| 360 | | ``[@attrib]`` | Selects all elements that have the given attribute. | |
| 361 | +-----------------------+------------------------------------------------------+ |
| 362 | | ``[@attrib='value']`` | Selects all elements for which the given attribute | |
| 363 | | | has the given value. The value cannot contain | |
| 364 | | | quotes. | |
| 365 | +-----------------------+------------------------------------------------------+ |
| 366 | | ``[tag]`` | Selects all elements that have a child named | |
| 367 | | | ``tag``. Only immediate children are supported. | |
| 368 | +-----------------------+------------------------------------------------------+ |
| 369 | | ``[position]`` | Selects all elements that are located at the given | |
| 370 | | | position. The position can be either an integer | |
| 371 | | | (1 is the first position), the expression ``last()`` | |
| 372 | | | (for the last position), or a position relative to | |
| 373 | | | the last position (e.g. ``last()-1``). | |
| 374 | +-----------------------+------------------------------------------------------+ |
| 375 | |
| 376 | Predicates (expressions within square brackets) must be preceded by a tag |
| 377 | name, an asterisk, or another predicate. ``position`` predicates must be |
| 378 | preceded by a tag name. |
| 379 | |
| 380 | Reference |
| 381 | --------- |
| 382 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 383 | .. _elementtree-functions: |
| 384 | |
| 385 | Functions |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 386 | ^^^^^^^^^ |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 387 | |
| 388 | |
Georg Brandl | 7f01a13 | 2009-09-16 15:58:14 +0000 | [diff] [blame] | 389 | .. function:: Comment(text=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 390 | |
Georg Brandl | f694518 | 2008-02-01 11:56:49 +0000 | [diff] [blame] | 391 | Comment element factory. This factory function creates a special element |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 392 | that will be serialized as an XML comment by the standard serializer. The |
| 393 | comment string can be either a bytestring or a Unicode string. *text* is a |
| 394 | string containing the comment string. Returns an element instance |
Georg Brandl | f694518 | 2008-02-01 11:56:49 +0000 | [diff] [blame] | 395 | representing a comment. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 396 | |
Eli Bendersky | 0bd22d4 | 2014-04-03 06:14:38 -0700 | [diff] [blame] | 397 | Note that :class:`XMLParser` skips over comments in the input |
| 398 | instead of creating comment objects for them. An :class:`ElementTree` will |
| 399 | only contain comment nodes if they have been inserted into to |
| 400 | the tree using one of the :class:`Element` methods. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 401 | |
| 402 | .. function:: dump(elem) |
| 403 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 404 | Writes an element tree or element structure to sys.stdout. This function |
| 405 | should be used for debugging only. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 406 | |
| 407 | The exact output format is implementation dependent. In this version, it's |
| 408 | written as an ordinary XML file. |
| 409 | |
| 410 | *elem* is an element tree or an individual element. |
| 411 | |
| 412 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 413 | .. function:: fromstring(text) |
| 414 | |
Florent Xicluna | dddd5e9 | 2010-03-14 01:28:07 +0000 | [diff] [blame] | 415 | Parses an XML section from a string constant. Same as :func:`XML`. *text* |
| 416 | is a string containing XML data. Returns an :class:`Element` instance. |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 417 | |
| 418 | |
| 419 | .. function:: fromstringlist(sequence, parser=None) |
| 420 | |
| 421 | Parses an XML document from a sequence of string fragments. *sequence* is a |
| 422 | list or other sequence containing XML data fragments. *parser* is an |
| 423 | optional parser instance. If not given, the standard :class:`XMLParser` |
| 424 | parser is used. Returns an :class:`Element` instance. |
| 425 | |
Ezio Melotti | f8754a6 | 2010-03-21 07:16:43 +0000 | [diff] [blame] | 426 | .. versionadded:: 3.2 |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 427 | |
| 428 | |
| 429 | .. function:: iselement(element) |
| 430 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 431 | Checks if an object appears to be a valid element object. *element* is an |
| 432 | element instance. Returns a true value if this is an element object. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 433 | |
| 434 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 435 | .. function:: iterparse(source, events=None, parser=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 436 | |
| 437 | 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] | 438 | 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] | 439 | 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] | 440 | supported events are the strings ``"start"``, ``"end"``, ``"start-ns"`` and |
| 441 | ``"end-ns"`` (the "ns" events are used to get detailed namespace |
Eli Bendersky | 604c4ff | 2012-03-16 08:41:30 +0200 | [diff] [blame] | 442 | information). If *events* is omitted, only ``"end"`` events are reported. |
| 443 | *parser* is an optional parser instance. If not given, the standard |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 444 | :class:`XMLParser` parser is used. *parser* must be a subclass of |
| 445 | :class:`XMLParser` and can only use the default :class:`TreeBuilder` as a |
| 446 | target. Returns an :term:`iterator` providing ``(event, elem)`` pairs. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 447 | |
Eli Bendersky | ab2a76c | 2013-04-20 05:53:50 -0700 | [diff] [blame] | 448 | Note that while :func:`iterparse` builds the tree incrementally, it issues |
| 449 | 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] | 450 | for applications where blocking reads can't be made. For fully non-blocking |
| 451 | parsing, see :class:`XMLPullParser`. |
Eli Bendersky | ab2a76c | 2013-04-20 05:53:50 -0700 | [diff] [blame] | 452 | |
Benjamin Peterson | 75edad0 | 2009-01-01 15:05:06 +0000 | [diff] [blame] | 453 | .. note:: |
| 454 | |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 455 | :func:`iterparse` only guarantees that it has seen the ">" character of a |
| 456 | starting tag when it emits a "start" event, so the attributes are defined, |
| 457 | but the contents of the text and tail attributes are undefined at that |
| 458 | point. The same applies to the element children; they may or may not be |
| 459 | present. |
Benjamin Peterson | 75edad0 | 2009-01-01 15:05:06 +0000 | [diff] [blame] | 460 | |
| 461 | If you need a fully populated element, look for "end" events instead. |
| 462 | |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 463 | .. deprecated:: 3.4 |
| 464 | The *parser* argument. |
| 465 | |
Georg Brandl | 7f01a13 | 2009-09-16 15:58:14 +0000 | [diff] [blame] | 466 | .. function:: parse(source, parser=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 467 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 468 | Parses an XML section into an element tree. *source* is a filename or file |
| 469 | object containing XML data. *parser* is an optional parser instance. If |
| 470 | not given, the standard :class:`XMLParser` parser is used. Returns an |
| 471 | :class:`ElementTree` instance. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 472 | |
| 473 | |
Georg Brandl | 7f01a13 | 2009-09-16 15:58:14 +0000 | [diff] [blame] | 474 | .. function:: ProcessingInstruction(target, text=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 475 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 476 | PI element factory. This factory function creates a special element that |
| 477 | will be serialized as an XML processing instruction. *target* is a string |
| 478 | containing the PI target. *text* is a string containing the PI contents, if |
| 479 | given. Returns an element instance, representing a processing instruction. |
| 480 | |
Eli Bendersky | 0bd22d4 | 2014-04-03 06:14:38 -0700 | [diff] [blame] | 481 | Note that :class:`XMLParser` skips over processing instructions |
| 482 | in the input instead of creating comment objects for them. An |
| 483 | :class:`ElementTree` will only contain processing instruction nodes if |
| 484 | they have been inserted into to the tree using one of the |
| 485 | :class:`Element` methods. |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 486 | |
| 487 | .. function:: register_namespace(prefix, uri) |
| 488 | |
| 489 | Registers a namespace prefix. The registry is global, and any existing |
| 490 | mapping for either the given prefix or the namespace URI will be removed. |
| 491 | *prefix* is a namespace prefix. *uri* is a namespace uri. Tags and |
| 492 | attributes in this namespace will be serialized with the given prefix, if at |
| 493 | all possible. |
| 494 | |
Ezio Melotti | f8754a6 | 2010-03-21 07:16:43 +0000 | [diff] [blame] | 495 | .. versionadded:: 3.2 |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 496 | |
| 497 | |
Georg Brandl | 7f01a13 | 2009-09-16 15:58:14 +0000 | [diff] [blame] | 498 | .. function:: SubElement(parent, tag, attrib={}, **extra) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 499 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 500 | Subelement factory. This function creates an element instance, and appends |
| 501 | it to an existing element. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 502 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 503 | The element name, attribute names, and attribute values can be either |
| 504 | bytestrings or Unicode strings. *parent* is the parent element. *tag* is |
| 505 | the subelement name. *attrib* is an optional dictionary, containing element |
| 506 | attributes. *extra* contains additional attributes, given as keyword |
| 507 | arguments. Returns an element instance. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 508 | |
| 509 | |
Serhiy Storchaka | 9e189f0 | 2013-01-13 22:24:27 +0200 | [diff] [blame] | 510 | .. function:: tostring(element, encoding="us-ascii", method="xml", *, \ |
Eli Bendersky | a9a2ef5 | 2013-01-13 06:04:43 -0800 | [diff] [blame] | 511 | short_empty_elements=True) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 512 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 513 | Generates a string representation of an XML element, including all |
Florent Xicluna | dddd5e9 | 2010-03-14 01:28:07 +0000 | [diff] [blame] | 514 | subelements. *element* is an :class:`Element` instance. *encoding* [1]_ is |
Florent Xicluna | c17f172 | 2010-08-08 19:48:29 +0000 | [diff] [blame] | 515 | the output encoding (default is US-ASCII). Use ``encoding="unicode"`` to |
Eli Bendersky | 831893a | 2012-10-09 07:18:16 -0700 | [diff] [blame] | 516 | generate a Unicode string (otherwise, a bytestring is generated). *method* |
| 517 | is either ``"xml"``, ``"html"`` or ``"text"`` (default is ``"xml"``). |
Eli Bendersky | a9a2ef5 | 2013-01-13 06:04:43 -0800 | [diff] [blame] | 518 | *short_empty_elements* has the same meaning as in :meth:`ElementTree.write`. |
Eli Bendersky | 831893a | 2012-10-09 07:18:16 -0700 | [diff] [blame] | 519 | Returns an (optionally) encoded string containing the XML data. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 520 | |
Eli Bendersky | a9a2ef5 | 2013-01-13 06:04:43 -0800 | [diff] [blame] | 521 | .. versionadded:: 3.4 |
| 522 | The *short_empty_elements* parameter. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 523 | |
Eli Bendersky | a9a2ef5 | 2013-01-13 06:04:43 -0800 | [diff] [blame] | 524 | |
Serhiy Storchaka | 9e189f0 | 2013-01-13 22:24:27 +0200 | [diff] [blame] | 525 | .. function:: tostringlist(element, encoding="us-ascii", method="xml", *, \ |
Eli Bendersky | a9a2ef5 | 2013-01-13 06:04:43 -0800 | [diff] [blame] | 526 | short_empty_elements=True) |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 527 | |
| 528 | Generates a string representation of an XML element, including all |
Florent Xicluna | dddd5e9 | 2010-03-14 01:28:07 +0000 | [diff] [blame] | 529 | subelements. *element* is an :class:`Element` instance. *encoding* [1]_ is |
Florent Xicluna | c17f172 | 2010-08-08 19:48:29 +0000 | [diff] [blame] | 530 | the output encoding (default is US-ASCII). Use ``encoding="unicode"`` to |
Eli Bendersky | 831893a | 2012-10-09 07:18:16 -0700 | [diff] [blame] | 531 | generate a Unicode string (otherwise, a bytestring is generated). *method* |
| 532 | is either ``"xml"``, ``"html"`` or ``"text"`` (default is ``"xml"``). |
Eli Bendersky | a9a2ef5 | 2013-01-13 06:04:43 -0800 | [diff] [blame] | 533 | *short_empty_elements* has the same meaning as in :meth:`ElementTree.write`. |
Eli Bendersky | 831893a | 2012-10-09 07:18:16 -0700 | [diff] [blame] | 534 | Returns a list of (optionally) encoded strings containing the XML data. |
| 535 | It does not guarantee any specific sequence, except that |
Serhiy Storchaka | 5e028ae | 2014-02-06 21:10:41 +0200 | [diff] [blame] | 536 | ``b"".join(tostringlist(element)) == tostring(element)``. |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 537 | |
Ezio Melotti | f8754a6 | 2010-03-21 07:16:43 +0000 | [diff] [blame] | 538 | .. versionadded:: 3.2 |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 539 | |
Eli Bendersky | a9a2ef5 | 2013-01-13 06:04:43 -0800 | [diff] [blame] | 540 | .. versionadded:: 3.4 |
| 541 | The *short_empty_elements* parameter. |
| 542 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 543 | |
| 544 | .. function:: XML(text, parser=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 545 | |
| 546 | 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] | 547 | embed "XML literals" in Python code. *text* is a string containing XML |
| 548 | data. *parser* is an optional parser instance. If not given, the standard |
| 549 | :class:`XMLParser` parser is used. Returns an :class:`Element` instance. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 550 | |
| 551 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 552 | .. function:: XMLID(text, parser=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 553 | |
| 554 | 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] | 555 | which maps from element id:s to elements. *text* is a string containing XML |
| 556 | data. *parser* is an optional parser instance. If not given, the standard |
| 557 | :class:`XMLParser` parser is used. Returns a tuple containing an |
| 558 | :class:`Element` instance and a dictionary. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 559 | |
| 560 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 561 | .. _elementtree-element-objects: |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 562 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 563 | Element Objects |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 564 | ^^^^^^^^^^^^^^^ |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 565 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 566 | .. class:: Element(tag, attrib={}, **extra) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 567 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 568 | Element class. This class defines the Element interface, and provides a |
| 569 | reference implementation of this interface. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 570 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 571 | The element name, attribute names, and attribute values can be either |
| 572 | bytestrings or Unicode strings. *tag* is the element name. *attrib* is |
| 573 | an optional dictionary, containing element attributes. *extra* contains |
| 574 | additional attributes, given as keyword arguments. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 575 | |
| 576 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 577 | .. attribute:: tag |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 578 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 579 | A string identifying what kind of data this element represents (the |
| 580 | element type, in other words). |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 581 | |
| 582 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 583 | .. attribute:: text |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 584 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 585 | The *text* attribute can be used to hold additional data associated with |
| 586 | the element. As the name implies this attribute is usually a string but |
| 587 | may be any application-specific object. If the element is created from |
| 588 | an XML file the attribute will contain any text found between the element |
| 589 | tags. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 590 | |
| 591 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 592 | .. attribute:: tail |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 593 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 594 | The *tail* attribute can be used to hold additional data associated with |
| 595 | the element. This attribute is usually a string but may be any |
| 596 | application-specific object. If the element is created from an XML file |
| 597 | the attribute will contain any text found after the element's end tag and |
| 598 | before the next tag. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 599 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 600 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 601 | .. attribute:: attrib |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 602 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 603 | A dictionary containing the element's attributes. Note that while the |
| 604 | *attrib* value is always a real mutable Python dictionary, an ElementTree |
| 605 | implementation may choose to use another internal representation, and |
| 606 | create the dictionary only if someone asks for it. To take advantage of |
| 607 | such implementations, use the dictionary methods below whenever possible. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 608 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 609 | The following dictionary-like methods work on the element attributes. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 610 | |
| 611 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 612 | .. method:: clear() |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 613 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 614 | Resets an element. This function removes all subelements, clears all |
Eli Bendersky | 323a43a | 2012-10-09 06:46:33 -0700 | [diff] [blame] | 615 | attributes, and sets the text and tail attributes to ``None``. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 616 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 617 | |
| 618 | .. method:: get(key, default=None) |
| 619 | |
| 620 | Gets the element attribute named *key*. |
| 621 | |
| 622 | Returns the attribute value, or *default* if the attribute was not found. |
| 623 | |
| 624 | |
| 625 | .. method:: items() |
| 626 | |
| 627 | Returns the element attributes as a sequence of (name, value) pairs. The |
| 628 | attributes are returned in an arbitrary order. |
| 629 | |
| 630 | |
| 631 | .. method:: keys() |
| 632 | |
| 633 | Returns the elements attribute names as a list. The names are returned |
| 634 | in an arbitrary order. |
| 635 | |
| 636 | |
| 637 | .. method:: set(key, value) |
| 638 | |
| 639 | Set the attribute *key* on the element to *value*. |
| 640 | |
| 641 | The following methods work on the element's children (subelements). |
| 642 | |
| 643 | |
| 644 | .. method:: append(subelement) |
| 645 | |
Eli Bendersky | 396e8fc | 2012-03-23 14:24:20 +0200 | [diff] [blame] | 646 | Adds the element *subelement* to the end of this element's internal list |
| 647 | of subelements. Raises :exc:`TypeError` if *subelement* is not an |
| 648 | :class:`Element`. |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 649 | |
| 650 | |
| 651 | .. method:: extend(subelements) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 652 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 653 | Appends *subelements* from a sequence object with zero or more elements. |
Eli Bendersky | 396e8fc | 2012-03-23 14:24:20 +0200 | [diff] [blame] | 654 | Raises :exc:`TypeError` if a subelement is not an :class:`Element`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 655 | |
Ezio Melotti | f8754a6 | 2010-03-21 07:16:43 +0000 | [diff] [blame] | 656 | .. versionadded:: 3.2 |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 657 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 658 | |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 659 | .. method:: find(match, namespaces=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 660 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 661 | Finds the first subelement matching *match*. *match* may be a tag name |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 662 | or a :ref:`path <elementtree-xpath>`. Returns an element instance |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 663 | or ``None``. *namespaces* is an optional mapping from namespace prefix |
| 664 | to full name. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 665 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 666 | |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 667 | .. method:: findall(match, namespaces=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 668 | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 669 | Finds all matching subelements, by tag name or |
| 670 | :ref:`path <elementtree-xpath>`. Returns a list containing all matching |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 671 | elements in document order. *namespaces* is an optional mapping from |
| 672 | namespace prefix to full name. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 673 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 674 | |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 675 | .. method:: findtext(match, default=None, namespaces=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 676 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 677 | Finds text for the first subelement matching *match*. *match* may be |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 678 | a tag name or a :ref:`path <elementtree-xpath>`. Returns the text content |
| 679 | of the first matching element, or *default* if no element was found. |
| 680 | 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] | 681 | is returned. *namespaces* is an optional mapping from namespace prefix |
| 682 | to full name. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 683 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 684 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 685 | .. method:: getchildren() |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 686 | |
Georg Brandl | 67b21b7 | 2010-08-17 15:07:14 +0000 | [diff] [blame] | 687 | .. deprecated:: 3.2 |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 688 | Use ``list(elem)`` or iteration. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 689 | |
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 | .. method:: getiterator(tag=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 692 | |
Georg Brandl | 67b21b7 | 2010-08-17 15:07:14 +0000 | [diff] [blame] | 693 | .. deprecated:: 3.2 |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 694 | Use method :meth:`Element.iter` instead. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 695 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 696 | |
Eli Bendersky | 396e8fc | 2012-03-23 14:24:20 +0200 | [diff] [blame] | 697 | .. method:: insert(index, subelement) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 698 | |
Eli Bendersky | 396e8fc | 2012-03-23 14:24:20 +0200 | [diff] [blame] | 699 | Inserts *subelement* at the given position in this element. Raises |
| 700 | :exc:`TypeError` if *subelement* is not an :class:`Element`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 701 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 702 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 703 | .. method:: iter(tag=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 | Creates a tree :term:`iterator` with the current element as the root. |
| 706 | The iterator iterates over this element and all elements below it, in |
| 707 | document (depth first) order. If *tag* is not ``None`` or ``'*'``, only |
| 708 | elements whose tag equals *tag* are returned from the iterator. If the |
| 709 | tree structure is modified during iteration, the result is undefined. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 710 | |
Ezio Melotti | 138fc89 | 2011-10-10 00:02:03 +0300 | [diff] [blame] | 711 | .. versionadded:: 3.2 |
| 712 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 713 | |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 714 | .. method:: iterfind(match, namespaces=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 715 | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 716 | Finds all matching subelements, by tag name or |
| 717 | :ref:`path <elementtree-xpath>`. Returns an iterable yielding all |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 718 | matching elements in document order. *namespaces* is an optional mapping |
| 719 | from namespace prefix to full name. |
| 720 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 721 | |
Ezio Melotti | f8754a6 | 2010-03-21 07:16:43 +0000 | [diff] [blame] | 722 | .. versionadded:: 3.2 |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 723 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 724 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 725 | .. method:: itertext() |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 726 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 727 | Creates a text iterator. The iterator loops over this element and all |
| 728 | subelements, in document order, and returns all inner text. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 729 | |
Ezio Melotti | f8754a6 | 2010-03-21 07:16:43 +0000 | [diff] [blame] | 730 | .. versionadded:: 3.2 |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 731 | |
| 732 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 733 | .. method:: makeelement(tag, attrib) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 734 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 735 | Creates a new element object of the same type as this element. Do not |
| 736 | call this method, use the :func:`SubElement` factory function instead. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 737 | |
| 738 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 739 | .. method:: remove(subelement) |
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 | Removes *subelement* from the element. Unlike the find\* methods this |
| 742 | method compares elements based on the instance identity, not on tag value |
| 743 | or contents. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 744 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 745 | :class:`Element` objects also support the following sequence type methods |
Serhiy Storchaka | 15e6590 | 2013-08-29 10:28:44 +0300 | [diff] [blame] | 746 | for working with subelements: :meth:`~object.__delitem__`, |
| 747 | :meth:`~object.__getitem__`, :meth:`~object.__setitem__`, |
| 748 | :meth:`~object.__len__`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 749 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 750 | Caution: Elements with no subelements will test as ``False``. This behavior |
| 751 | will change in future versions. Use specific ``len(elem)`` or ``elem is |
| 752 | None`` test instead. :: |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 753 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 754 | element = root.find('foo') |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 755 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 756 | if not element: # careful! |
| 757 | print("element not found, or element has no subelements") |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 758 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 759 | if element is None: |
| 760 | print("element not found") |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 761 | |
| 762 | |
| 763 | .. _elementtree-elementtree-objects: |
| 764 | |
| 765 | ElementTree Objects |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 766 | ^^^^^^^^^^^^^^^^^^^ |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 767 | |
| 768 | |
Georg Brandl | 7f01a13 | 2009-09-16 15:58:14 +0000 | [diff] [blame] | 769 | .. class:: ElementTree(element=None, file=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 770 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 771 | ElementTree wrapper class. This class represents an entire element |
| 772 | hierarchy, and adds some extra support for serialization to and from |
| 773 | standard XML. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 774 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 775 | *element* is the root element. The tree is initialized with the contents |
| 776 | of the XML *file* if given. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 777 | |
| 778 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 779 | .. method:: _setroot(element) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 780 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 781 | Replaces the root element for this tree. This discards the current |
| 782 | 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] | 783 | care. *element* is an element instance. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 784 | |
| 785 | |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 786 | .. method:: find(match, namespaces=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 787 | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 788 | Same as :meth:`Element.find`, starting at the root of the tree. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 789 | |
| 790 | |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 791 | .. method:: findall(match, namespaces=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 792 | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 793 | Same as :meth:`Element.findall`, starting at the root of the tree. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 794 | |
| 795 | |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 796 | .. method:: findtext(match, default=None, namespaces=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 797 | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 798 | Same as :meth:`Element.findtext`, starting at the root of the tree. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 799 | |
| 800 | |
Georg Brandl | 7f01a13 | 2009-09-16 15:58:14 +0000 | [diff] [blame] | 801 | .. method:: getiterator(tag=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 802 | |
Georg Brandl | 67b21b7 | 2010-08-17 15:07:14 +0000 | [diff] [blame] | 803 | .. deprecated:: 3.2 |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 804 | Use method :meth:`ElementTree.iter` instead. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 805 | |
| 806 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 807 | .. method:: getroot() |
Florent Xicluna | c17f172 | 2010-08-08 19:48:29 +0000 | [diff] [blame] | 808 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 809 | Returns the root element for this tree. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 810 | |
| 811 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 812 | .. method:: iter(tag=None) |
| 813 | |
| 814 | Creates and returns a tree iterator for the root element. The iterator |
| 815 | loops over all elements in this tree, in section order. *tag* is the tag |
| 816 | to look for (default is to return all elements) |
| 817 | |
| 818 | |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 819 | .. method:: iterfind(match, namespaces=None) |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 820 | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 821 | Same as :meth:`Element.iterfind`, starting at the root of the tree. |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 822 | |
Ezio Melotti | f8754a6 | 2010-03-21 07:16:43 +0000 | [diff] [blame] | 823 | .. versionadded:: 3.2 |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 824 | |
| 825 | |
Georg Brandl | 7f01a13 | 2009-09-16 15:58:14 +0000 | [diff] [blame] | 826 | .. method:: parse(source, parser=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 827 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 828 | 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] | 829 | name or :term:`file object`. *parser* is an optional parser instance. |
Eli Bendersky | 52467b1 | 2012-06-01 07:13:08 +0300 | [diff] [blame] | 830 | If not given, the standard :class:`XMLParser` parser is used. Returns the |
| 831 | section root element. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 832 | |
| 833 | |
Eli Bendersky | f96cf91 | 2012-07-15 06:19:44 +0300 | [diff] [blame] | 834 | .. method:: write(file, encoding="us-ascii", xml_declaration=None, \ |
Serhiy Storchaka | 9e189f0 | 2013-01-13 22:24:27 +0200 | [diff] [blame] | 835 | default_namespace=None, method="xml", *, \ |
Eli Bendersky | e9af827 | 2013-01-13 06:27:51 -0800 | [diff] [blame] | 836 | short_empty_elements=True) |
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 | 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] | 839 | :term:`file object` opened for writing. *encoding* [1]_ is the output |
| 840 | encoding (default is US-ASCII). |
| 841 | *xml_declaration* controls if an XML declaration should be added to the |
| 842 | file. Use ``False`` for never, ``True`` for always, ``None`` |
| 843 | 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] | 844 | *default_namespace* sets the default XML namespace (for "xmlns"). |
Eli Bendersky | f96cf91 | 2012-07-15 06:19:44 +0300 | [diff] [blame] | 845 | *method* is either ``"xml"``, ``"html"`` or ``"text"`` (default is |
| 846 | ``"xml"``). |
Eli Bendersky | a9a2ef5 | 2013-01-13 06:04:43 -0800 | [diff] [blame] | 847 | The keyword-only *short_empty_elements* parameter controls the formatting |
| 848 | of elements that contain no content. If *True* (the default), they are |
| 849 | emitted as a single self-closed tag, otherwise they are emitted as a pair |
| 850 | of start/end tags. |
Eli Bendersky | f96cf91 | 2012-07-15 06:19:44 +0300 | [diff] [blame] | 851 | |
| 852 | The output is either a string (:class:`str`) or binary (:class:`bytes`). |
| 853 | This is controlled by the *encoding* argument. If *encoding* is |
| 854 | ``"unicode"``, the output is a string; otherwise, it's binary. Note that |
| 855 | this may conflict with the type of *file* if it's an open |
| 856 | :term:`file object`; make sure you do not try to write a string to a |
| 857 | binary stream and vice versa. |
| 858 | |
R David Murray | 575fb31 | 2013-12-25 23:21:03 -0500 | [diff] [blame] | 859 | .. versionadded:: 3.4 |
| 860 | The *short_empty_elements* parameter. |
Eli Bendersky | a9a2ef5 | 2013-01-13 06:04:43 -0800 | [diff] [blame] | 861 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 862 | |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 863 | This is the XML file that is going to be manipulated:: |
| 864 | |
| 865 | <html> |
| 866 | <head> |
| 867 | <title>Example page</title> |
| 868 | </head> |
| 869 | <body> |
Georg Brandl | 48310cd | 2009-01-03 21:18:54 +0000 | [diff] [blame] | 870 | <p>Moved to <a href="http://example.org/">example.org</a> |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 871 | or <a href="http://example.com/">example.com</a>.</p> |
| 872 | </body> |
| 873 | </html> |
| 874 | |
| 875 | Example of changing the attribute "target" of every link in first paragraph:: |
| 876 | |
| 877 | >>> from xml.etree.ElementTree import ElementTree |
| 878 | >>> tree = ElementTree() |
| 879 | >>> tree.parse("index.xhtml") |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 880 | <Element 'html' at 0xb77e6fac> |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 881 | >>> p = tree.find("body/p") # Finds first occurrence of tag p in body |
| 882 | >>> p |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 883 | <Element 'p' at 0xb77ec26c> |
| 884 | >>> links = list(p.iter("a")) # Returns list of all links |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 885 | >>> links |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 886 | [<Element 'a' at 0xb77ec2ac>, <Element 'a' at 0xb77ec1cc>] |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 887 | >>> for i in links: # Iterates through all found links |
| 888 | ... i.attrib["target"] = "blank" |
| 889 | >>> tree.write("output.xhtml") |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 890 | |
| 891 | .. _elementtree-qname-objects: |
| 892 | |
| 893 | QName Objects |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 894 | ^^^^^^^^^^^^^ |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 895 | |
| 896 | |
Georg Brandl | 7f01a13 | 2009-09-16 15:58:14 +0000 | [diff] [blame] | 897 | .. class:: QName(text_or_uri, tag=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 898 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 899 | QName wrapper. This can be used to wrap a QName attribute value, in order |
| 900 | to get proper namespace handling on output. *text_or_uri* is a string |
| 901 | containing the QName value, in the form {uri}local, or, if the tag argument |
| 902 | is given, the URI part of a QName. If *tag* is given, the first argument is |
| 903 | interpreted as an URI, and this argument is interpreted as a local name. |
| 904 | :class:`QName` instances are opaque. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 905 | |
| 906 | |
Antoine Pitrou | 5b235d0 | 2013-04-18 19:37:06 +0200 | [diff] [blame] | 907 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 908 | .. _elementtree-treebuilder-objects: |
| 909 | |
| 910 | TreeBuilder Objects |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 911 | ^^^^^^^^^^^^^^^^^^^ |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 912 | |
| 913 | |
Georg Brandl | 7f01a13 | 2009-09-16 15:58:14 +0000 | [diff] [blame] | 914 | .. class:: TreeBuilder(element_factory=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 | Generic element structure builder. This builder converts a sequence of |
| 917 | start, data, and end method calls to a well-formed element structure. You |
| 918 | 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] | 919 | or a parser for some other XML-like format. *element_factory*, when given, |
| 920 | must be a callable accepting two positional arguments: a tag and |
| 921 | 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] | 922 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 923 | .. method:: close() |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 924 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 925 | Flushes the builder buffers, and returns the toplevel document |
| 926 | element. Returns an :class:`Element` instance. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 927 | |
| 928 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 929 | .. method:: data(data) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 930 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 931 | Adds text to the current element. *data* is a string. This should be |
| 932 | either a bytestring, or a Unicode string. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 933 | |
| 934 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 935 | .. method:: end(tag) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 936 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 937 | Closes the current element. *tag* is the element name. Returns the |
| 938 | closed element. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 939 | |
| 940 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 941 | .. method:: start(tag, attrs) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 942 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 943 | Opens a new element. *tag* is the element name. *attrs* is a dictionary |
| 944 | containing element attributes. Returns the opened element. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 945 | |
| 946 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 947 | In addition, a custom :class:`TreeBuilder` object can provide the |
| 948 | following method: |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 949 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 950 | .. method:: doctype(name, pubid, system) |
| 951 | |
| 952 | Handles a doctype declaration. *name* is the doctype name. *pubid* is |
| 953 | the public identifier. *system* is the system identifier. This method |
| 954 | does not exist on the default :class:`TreeBuilder` class. |
| 955 | |
Ezio Melotti | f8754a6 | 2010-03-21 07:16:43 +0000 | [diff] [blame] | 956 | .. versionadded:: 3.2 |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 957 | |
| 958 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 959 | .. _elementtree-xmlparser-objects: |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 960 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 961 | XMLParser Objects |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 962 | ^^^^^^^^^^^^^^^^^ |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 963 | |
| 964 | |
| 965 | .. class:: XMLParser(html=0, target=None, encoding=None) |
| 966 | |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 967 | This class is the low-level building block of the module. It uses |
| 968 | :mod:`xml.parsers.expat` for efficient, event-based parsing of XML. It can |
| 969 | be fed XML data incrementall with the :meth:`feed` method, and parsing events |
| 970 | are translated to a push API - by invoking callbacks on the *target* object. |
| 971 | If *target* is omitted, the standard :class:`TreeBuilder` is used. The |
| 972 | *html* argument was historically used for backwards compatibility and is now |
| 973 | deprecated. If *encoding* [1]_ is given, the value overrides the encoding |
Eli Bendersky | 52467b1 | 2012-06-01 07:13:08 +0300 | [diff] [blame] | 974 | specified in the XML file. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 975 | |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 976 | .. deprecated:: 3.4 |
Larry Hastings | 3732ed2 | 2014-03-15 21:13:56 -0700 | [diff] [blame] | 977 | The *html* argument. The remaining arguments should be passed via |
| 978 | keywword to prepare for the removal of the *html* argument. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 979 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 980 | .. method:: close() |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 981 | |
Eli Bendersky | bfd7837 | 2013-08-24 15:11:44 -0700 | [diff] [blame] | 982 | Finishes feeding data to the parser. Returns the result of calling the |
Eli Bendersky | bf8ab77 | 2013-08-25 15:27:36 -0700 | [diff] [blame] | 983 | ``close()`` method of the *target* passed during construction; by default, |
| 984 | this is the toplevel document element. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 985 | |
| 986 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 987 | .. method:: doctype(name, pubid, system) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 988 | |
Georg Brandl | 67b21b7 | 2010-08-17 15:07:14 +0000 | [diff] [blame] | 989 | .. deprecated:: 3.2 |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 990 | Define the :meth:`TreeBuilder.doctype` method on a custom TreeBuilder |
| 991 | target. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 992 | |
| 993 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 994 | .. method:: feed(data) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 995 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 996 | Feeds data to the parser. *data* is encoded data. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 997 | |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 998 | :meth:`XMLParser.feed` calls *target*\'s ``start(tag, attrs_dict)`` method |
| 999 | for each opening tag, its ``end(tag)`` method for each closing tag, and data |
| 1000 | is processed by method ``data(data)``. :meth:`XMLParser.close` calls |
| 1001 | *target*\'s method ``close()``. :class:`XMLParser` can be used not only for |
| 1002 | building a tree structure. This is an example of counting the maximum depth |
| 1003 | of an XML file:: |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 1004 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 1005 | >>> from xml.etree.ElementTree import XMLParser |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 1006 | >>> class MaxDepth: # The target object of the parser |
| 1007 | ... maxDepth = 0 |
| 1008 | ... depth = 0 |
| 1009 | ... def start(self, tag, attrib): # Called for each opening tag. |
Georg Brandl | 48310cd | 2009-01-03 21:18:54 +0000 | [diff] [blame] | 1010 | ... self.depth += 1 |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 1011 | ... if self.depth > self.maxDepth: |
| 1012 | ... self.maxDepth = self.depth |
| 1013 | ... def end(self, tag): # Called for each closing tag. |
| 1014 | ... self.depth -= 1 |
Georg Brandl | 48310cd | 2009-01-03 21:18:54 +0000 | [diff] [blame] | 1015 | ... def data(self, data): |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 1016 | ... pass # We do not need to do anything with data. |
| 1017 | ... def close(self): # Called when all data has been parsed. |
| 1018 | ... return self.maxDepth |
Georg Brandl | 48310cd | 2009-01-03 21:18:54 +0000 | [diff] [blame] | 1019 | ... |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 1020 | >>> target = MaxDepth() |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 1021 | >>> parser = XMLParser(target=target) |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 1022 | >>> exampleXml = """ |
| 1023 | ... <a> |
| 1024 | ... <b> |
| 1025 | ... </b> |
| 1026 | ... <b> |
| 1027 | ... <c> |
| 1028 | ... <d> |
| 1029 | ... </d> |
| 1030 | ... </c> |
| 1031 | ... </b> |
| 1032 | ... </a>""" |
| 1033 | >>> parser.feed(exampleXml) |
| 1034 | >>> parser.close() |
| 1035 | 4 |
Christian Heimes | b186d00 | 2008-03-18 15:15:01 +0000 | [diff] [blame] | 1036 | |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 1037 | |
| 1038 | .. _elementtree-xmlpullparser-objects: |
| 1039 | |
| 1040 | XMLPullParser Objects |
| 1041 | ^^^^^^^^^^^^^^^^^^^^^ |
| 1042 | |
| 1043 | .. class:: XMLPullParser(events=None) |
| 1044 | |
Eli Bendersky | 2c68e30 | 2013-08-31 07:37:23 -0700 | [diff] [blame] | 1045 | A pull parser suitable for non-blocking applications. Its input-side API is |
| 1046 | similar to that of :class:`XMLParser`, but instead of pushing calls to a |
| 1047 | callback target, :class:`XMLPullParser` collects an internal list of parsing |
| 1048 | events and lets the user read from it. *events* is a sequence of events to |
| 1049 | report back. The supported events are the strings ``"start"``, ``"end"``, |
| 1050 | ``"start-ns"`` and ``"end-ns"`` (the "ns" events are used to get detailed |
| 1051 | namespace information). If *events* is omitted, only ``"end"`` events are |
| 1052 | reported. |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 1053 | |
| 1054 | .. method:: feed(data) |
| 1055 | |
| 1056 | Feed the given bytes data to the parser. |
| 1057 | |
| 1058 | .. method:: close() |
| 1059 | |
Nick Coghlan | 4cc2afa | 2013-09-28 23:50:35 +1000 | [diff] [blame] | 1060 | Signal the parser that the data stream is terminated. Unlike |
| 1061 | :meth:`XMLParser.close`, this method always returns :const:`None`. |
| 1062 | Any events not yet retrieved when the parser is closed can still be |
| 1063 | read with :meth:`read_events`. |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 1064 | |
| 1065 | .. method:: read_events() |
| 1066 | |
R David Murray | 410d320 | 2014-01-04 23:52:50 -0500 | [diff] [blame] | 1067 | Return an iterator over the events which have been encountered in the |
| 1068 | data fed to the |
| 1069 | parser. The iterator yields ``(event, elem)`` pairs, where *event* is a |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 1070 | 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] | 1071 | encountered :class:`Element` object. |
| 1072 | |
| 1073 | 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] | 1074 | yielded again. Events are consumed from the internal queue only when |
| 1075 | they are retrieved from the iterator, so multiple readers iterating in |
| 1076 | parallel over iterators obtained from :meth:`read_events` will have |
| 1077 | unpredictable results. |
Eli Bendersky | b586934 | 2013-08-30 05:51:20 -0700 | [diff] [blame] | 1078 | |
| 1079 | .. note:: |
| 1080 | |
| 1081 | :class:`XMLPullParser` only guarantees that it has seen the ">" |
| 1082 | character of a starting tag when it emits a "start" event, so the |
| 1083 | attributes are defined, but the contents of the text and tail attributes |
| 1084 | are undefined at that point. The same applies to the element children; |
| 1085 | they may or may not be present. |
| 1086 | |
| 1087 | If you need a fully populated element, look for "end" events instead. |
| 1088 | |
| 1089 | .. versionadded:: 3.4 |
| 1090 | |
Eli Bendersky | 5b77d81 | 2012-03-16 08:20:05 +0200 | [diff] [blame] | 1091 | Exceptions |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 1092 | ^^^^^^^^^^ |
Eli Bendersky | 5b77d81 | 2012-03-16 08:20:05 +0200 | [diff] [blame] | 1093 | |
| 1094 | .. class:: ParseError |
| 1095 | |
| 1096 | XML parse error, raised by the various parsing methods in this module when |
| 1097 | parsing fails. The string representation of an instance of this exception |
| 1098 | will contain a user-friendly error message. In addition, it will have |
| 1099 | the following attributes available: |
| 1100 | |
| 1101 | .. attribute:: code |
| 1102 | |
| 1103 | A numeric error code from the expat parser. See the documentation of |
| 1104 | :mod:`xml.parsers.expat` for the list of error codes and their meanings. |
| 1105 | |
| 1106 | .. attribute:: position |
| 1107 | |
| 1108 | A tuple of *line*, *column* numbers, specifying where the error occurred. |
Christian Heimes | b186d00 | 2008-03-18 15:15:01 +0000 | [diff] [blame] | 1109 | |
| 1110 | .. rubric:: Footnotes |
| 1111 | |
| 1112 | .. [#] The encoding string included in XML output should conform to the |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 1113 | appropriate standards. For example, "UTF-8" is valid, but "UTF8" is |
| 1114 | not. See http://www.w3.org/TR/2006/REC-xml11-20060816/#NT-EncodingDecl |
Benjamin Peterson | ad3d5c2 | 2009-02-26 03:38:59 +0000 | [diff] [blame] | 1115 | and http://www.iana.org/assignments/character-sets. |