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 | |
Eli Bendersky | 3bdead1 | 2013-04-20 09:06:27 -0700 | [diff] [blame] | 108 | Incremental parsing |
| 109 | ^^^^^^^^^^^^^^^^^^^ |
| 110 | |
| 111 | It's possible to parse XML incrementally (i.e. not the whole document at once). |
| 112 | The most powerful tool for doing this is :class:`IncrementalParser`. It does |
| 113 | not require a blocking read to obtain the XML data, and is instead fed with |
| 114 | data incrementally with :meth:`IncrementalParser.data_received` calls. To get |
| 115 | the parsed XML elements, call :meth:`IncrementalParser.events`. Here's an |
| 116 | example:: |
| 117 | |
| 118 | >>> incparser = ET.IncrementalParser(['start', 'end']) |
| 119 | >>> incparser.data_received('<mytag>sometext') |
| 120 | >>> list(incparser.events()) |
| 121 | [('start', <Element 'mytag' at 0x7fba3f2a8688>)] |
| 122 | >>> incparser.data_received(' more text</mytag>') |
| 123 | >>> for event, elem in incparser.events(): |
| 124 | ... print(event) |
| 125 | ... print(elem.tag, 'text=', elem.text) |
| 126 | ... |
| 127 | end |
| 128 | mytag text= sometext more text |
| 129 | |
| 130 | The obvious use case is applications that operate in an asynchronous fashion |
| 131 | where the XML data is being received from a socket or read incrementally from |
| 132 | some storage device. In such cases, blocking reads are unacceptable. |
| 133 | |
| 134 | Because it's so flexible, :class:`IncrementalParser` can be inconvenient |
| 135 | to use for simpler use-cases. If you don't mind your application blocking on |
| 136 | reading XML data but would still like to have incremental parsing capabilities, |
| 137 | take a look at :func:`iterparse`. It can be useful when you're reading a large |
| 138 | XML document and don't want to hold it wholly in memory. |
| 139 | |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 140 | Finding interesting elements |
| 141 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ |
| 142 | |
| 143 | :class:`Element` has some useful methods that help iterate recursively over all |
| 144 | the sub-tree below it (its children, their children, and so on). For example, |
| 145 | :meth:`Element.iter`:: |
| 146 | |
| 147 | >>> for neighbor in root.iter('neighbor'): |
| 148 | ... print(neighbor.attrib) |
| 149 | ... |
| 150 | {'name': 'Austria', 'direction': 'E'} |
| 151 | {'name': 'Switzerland', 'direction': 'W'} |
| 152 | {'name': 'Malaysia', 'direction': 'N'} |
| 153 | {'name': 'Costa Rica', 'direction': 'W'} |
| 154 | {'name': 'Colombia', 'direction': 'E'} |
| 155 | |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 156 | :meth:`Element.findall` finds only elements with a tag which are direct |
| 157 | children of the current element. :meth:`Element.find` finds the *first* child |
| 158 | with a particular tag, and :meth:`Element.text` accesses the element's text |
| 159 | content. :meth:`Element.get` accesses the element's attributes:: |
| 160 | |
| 161 | >>> for country in root.findall('country'): |
| 162 | ... rank = country.find('rank').text |
| 163 | ... name = country.get('name') |
| 164 | ... print(name, rank) |
| 165 | ... |
Eli Bendersky | 3115f0d | 2012-08-15 14:26:30 +0300 | [diff] [blame] | 166 | Liechtenstein 1 |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 167 | Singapore 4 |
| 168 | Panama 68 |
| 169 | |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 170 | More sophisticated specification of which elements to look for is possible by |
| 171 | using :ref:`XPath <elementtree-xpath>`. |
| 172 | |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 173 | Modifying an XML File |
| 174 | ^^^^^^^^^^^^^^^^^^^^^ |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 175 | |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 176 | :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] | 177 | The :meth:`ElementTree.write` method serves this purpose. |
| 178 | |
| 179 | Once created, an :class:`Element` object may be manipulated by directly changing |
| 180 | its fields (such as :attr:`Element.text`), adding and modifying attributes |
| 181 | (:meth:`Element.set` method), as well as adding new children (for example |
| 182 | with :meth:`Element.append`). |
| 183 | |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 184 | Let's say we want to add one to each country's rank, and add an ``updated`` |
| 185 | attribute to the rank element:: |
| 186 | |
| 187 | >>> for rank in root.iter('rank'): |
| 188 | ... new_rank = int(rank.text) + 1 |
| 189 | ... rank.text = str(new_rank) |
| 190 | ... rank.set('updated', 'yes') |
| 191 | ... |
Eli Bendersky | a1b0f6d | 2012-08-18 05:42:22 +0300 | [diff] [blame] | 192 | >>> tree.write('output.xml') |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 193 | |
| 194 | Our XML now looks like this: |
| 195 | |
| 196 | .. code-block:: xml |
| 197 | |
| 198 | <?xml version="1.0"?> |
| 199 | <data> |
Eli Bendersky | 3115f0d | 2012-08-15 14:26:30 +0300 | [diff] [blame] | 200 | <country name="Liechtenstein"> |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 201 | <rank updated="yes">2</rank> |
| 202 | <year>2008</year> |
| 203 | <gdppc>141100</gdppc> |
| 204 | <neighbor name="Austria" direction="E"/> |
| 205 | <neighbor name="Switzerland" direction="W"/> |
| 206 | </country> |
| 207 | <country name="Singapore"> |
| 208 | <rank updated="yes">5</rank> |
| 209 | <year>2011</year> |
| 210 | <gdppc>59900</gdppc> |
| 211 | <neighbor name="Malaysia" direction="N"/> |
| 212 | </country> |
| 213 | <country name="Panama"> |
| 214 | <rank updated="yes">69</rank> |
| 215 | <year>2011</year> |
| 216 | <gdppc>13600</gdppc> |
| 217 | <neighbor name="Costa Rica" direction="W"/> |
| 218 | <neighbor name="Colombia" direction="E"/> |
| 219 | </country> |
| 220 | </data> |
| 221 | |
| 222 | We can remove elements using :meth:`Element.remove`. Let's say we want to |
| 223 | remove all countries with a rank higher than 50:: |
| 224 | |
| 225 | >>> for country in root.findall('country'): |
| 226 | ... rank = int(country.find('rank').text) |
| 227 | ... if rank > 50: |
| 228 | ... root.remove(country) |
| 229 | ... |
Eli Bendersky | a1b0f6d | 2012-08-18 05:42:22 +0300 | [diff] [blame] | 230 | >>> tree.write('output.xml') |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 231 | |
| 232 | Our XML now looks like this: |
| 233 | |
| 234 | .. code-block:: xml |
| 235 | |
| 236 | <?xml version="1.0"?> |
| 237 | <data> |
Eli Bendersky | 3115f0d | 2012-08-15 14:26:30 +0300 | [diff] [blame] | 238 | <country name="Liechtenstein"> |
Eli Bendersky | 0f4e934 | 2012-08-14 07:19:33 +0300 | [diff] [blame] | 239 | <rank updated="yes">2</rank> |
| 240 | <year>2008</year> |
| 241 | <gdppc>141100</gdppc> |
| 242 | <neighbor name="Austria" direction="E"/> |
| 243 | <neighbor name="Switzerland" direction="W"/> |
| 244 | </country> |
| 245 | <country name="Singapore"> |
| 246 | <rank updated="yes">5</rank> |
| 247 | <year>2011</year> |
| 248 | <gdppc>59900</gdppc> |
| 249 | <neighbor name="Malaysia" direction="N"/> |
| 250 | </country> |
| 251 | </data> |
| 252 | |
| 253 | Building XML documents |
| 254 | ^^^^^^^^^^^^^^^^^^^^^^ |
| 255 | |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 256 | The :func:`SubElement` function also provides a convenient way to create new |
| 257 | sub-elements for a given element:: |
| 258 | |
| 259 | >>> a = ET.Element('a') |
| 260 | >>> b = ET.SubElement(a, 'b') |
| 261 | >>> c = ET.SubElement(a, 'c') |
| 262 | >>> d = ET.SubElement(c, 'd') |
| 263 | >>> ET.dump(a) |
| 264 | <a><b /><c><d /></c></a> |
| 265 | |
| 266 | Additional resources |
| 267 | ^^^^^^^^^^^^^^^^^^^^ |
| 268 | |
| 269 | See http://effbot.org/zone/element-index.htm for tutorials and links to other |
| 270 | docs. |
| 271 | |
| 272 | |
| 273 | .. _elementtree-xpath: |
| 274 | |
| 275 | XPath support |
| 276 | ------------- |
| 277 | |
| 278 | This module provides limited support for |
| 279 | `XPath expressions <http://www.w3.org/TR/xpath>`_ for locating elements in a |
| 280 | tree. The goal is to support a small subset of the abbreviated syntax; a full |
| 281 | XPath engine is outside the scope of the module. |
| 282 | |
| 283 | Example |
| 284 | ^^^^^^^ |
| 285 | |
| 286 | Here's an example that demonstrates some of the XPath capabilities of the |
| 287 | module. We'll be using the ``countrydata`` XML document from the |
| 288 | :ref:`Parsing XML <elementtree-parsing-xml>` section:: |
| 289 | |
| 290 | import xml.etree.ElementTree as ET |
| 291 | |
| 292 | root = ET.fromstring(countrydata) |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 293 | |
| 294 | # Top-level elements |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 295 | root.findall(".") |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 296 | |
| 297 | # All 'neighbor' grand-children of 'country' children of the top-level |
| 298 | # elements |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 299 | root.findall("./country/neighbor") |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 300 | |
| 301 | # Nodes with name='Singapore' that have a 'year' child |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 302 | root.findall(".//year/..[@name='Singapore']") |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 303 | |
| 304 | # 'year' nodes that are children of nodes with name='Singapore' |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 305 | root.findall(".//*[@name='Singapore']/year") |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 306 | |
| 307 | # All 'neighbor' nodes that are the second child of their parent |
Eli Bendersky | c1d9869 | 2012-03-30 11:44:15 +0300 | [diff] [blame] | 308 | root.findall(".//neighbor[2]") |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 309 | |
| 310 | Supported XPath syntax |
| 311 | ^^^^^^^^^^^^^^^^^^^^^^ |
| 312 | |
Georg Brandl | 44ea77b | 2013-03-28 13:28:44 +0100 | [diff] [blame] | 313 | .. tabularcolumns:: |l|L| |
| 314 | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 315 | +-----------------------+------------------------------------------------------+ |
| 316 | | Syntax | Meaning | |
| 317 | +=======================+======================================================+ |
| 318 | | ``tag`` | Selects all child elements with the given tag. | |
| 319 | | | For example, ``spam`` selects all child elements | |
| 320 | | | named ``spam``, ``spam/egg`` selects all | |
| 321 | | | grandchildren named ``egg`` in all children named | |
| 322 | | | ``spam``. | |
| 323 | +-----------------------+------------------------------------------------------+ |
| 324 | | ``*`` | Selects all child elements. For example, ``*/egg`` | |
| 325 | | | selects all grandchildren named ``egg``. | |
| 326 | +-----------------------+------------------------------------------------------+ |
| 327 | | ``.`` | Selects the current node. This is mostly useful | |
| 328 | | | at the beginning of the path, to indicate that it's | |
| 329 | | | a relative path. | |
| 330 | +-----------------------+------------------------------------------------------+ |
| 331 | | ``//`` | Selects all subelements, on all levels beneath the | |
Eli Bendersky | ede001a | 2012-03-27 04:57:23 +0200 | [diff] [blame] | 332 | | | current element. For example, ``.//egg`` selects | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 333 | | | all ``egg`` elements in the entire tree. | |
| 334 | +-----------------------+------------------------------------------------------+ |
Eli Bendersky | 323a43a | 2012-10-09 06:46:33 -0700 | [diff] [blame] | 335 | | ``..`` | Selects the parent element. Returns ``None`` if the | |
| 336 | | | path attempts to reach the ancestors of the start | |
| 337 | | | element (the element ``find`` was called on). | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 338 | +-----------------------+------------------------------------------------------+ |
| 339 | | ``[@attrib]`` | Selects all elements that have the given attribute. | |
| 340 | +-----------------------+------------------------------------------------------+ |
| 341 | | ``[@attrib='value']`` | Selects all elements for which the given attribute | |
| 342 | | | has the given value. The value cannot contain | |
| 343 | | | quotes. | |
| 344 | +-----------------------+------------------------------------------------------+ |
| 345 | | ``[tag]`` | Selects all elements that have a child named | |
| 346 | | | ``tag``. Only immediate children are supported. | |
| 347 | +-----------------------+------------------------------------------------------+ |
| 348 | | ``[position]`` | Selects all elements that are located at the given | |
| 349 | | | position. The position can be either an integer | |
| 350 | | | (1 is the first position), the expression ``last()`` | |
| 351 | | | (for the last position), or a position relative to | |
| 352 | | | the last position (e.g. ``last()-1``). | |
| 353 | +-----------------------+------------------------------------------------------+ |
| 354 | |
| 355 | Predicates (expressions within square brackets) must be preceded by a tag |
| 356 | name, an asterisk, or another predicate. ``position`` predicates must be |
| 357 | preceded by a tag name. |
| 358 | |
| 359 | Reference |
| 360 | --------- |
| 361 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 362 | .. _elementtree-functions: |
| 363 | |
| 364 | Functions |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 365 | ^^^^^^^^^ |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 366 | |
| 367 | |
Georg Brandl | 7f01a13 | 2009-09-16 15:58:14 +0000 | [diff] [blame] | 368 | .. function:: Comment(text=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 369 | |
Georg Brandl | f694518 | 2008-02-01 11:56:49 +0000 | [diff] [blame] | 370 | Comment element factory. This factory function creates a special element |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 371 | that will be serialized as an XML comment by the standard serializer. The |
| 372 | comment string can be either a bytestring or a Unicode string. *text* is a |
| 373 | string containing the comment string. Returns an element instance |
Georg Brandl | f694518 | 2008-02-01 11:56:49 +0000 | [diff] [blame] | 374 | representing a comment. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 375 | |
| 376 | |
| 377 | .. function:: dump(elem) |
| 378 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 379 | Writes an element tree or element structure to sys.stdout. This function |
| 380 | should be used for debugging only. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 381 | |
| 382 | The exact output format is implementation dependent. In this version, it's |
| 383 | written as an ordinary XML file. |
| 384 | |
| 385 | *elem* is an element tree or an individual element. |
| 386 | |
| 387 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 388 | .. function:: fromstring(text) |
| 389 | |
Florent Xicluna | dddd5e9 | 2010-03-14 01:28:07 +0000 | [diff] [blame] | 390 | Parses an XML section from a string constant. Same as :func:`XML`. *text* |
| 391 | is a string containing XML data. Returns an :class:`Element` instance. |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 392 | |
| 393 | |
| 394 | .. function:: fromstringlist(sequence, parser=None) |
| 395 | |
| 396 | Parses an XML document from a sequence of string fragments. *sequence* is a |
| 397 | list or other sequence containing XML data fragments. *parser* is an |
| 398 | optional parser instance. If not given, the standard :class:`XMLParser` |
| 399 | parser is used. Returns an :class:`Element` instance. |
| 400 | |
Ezio Melotti | f8754a6 | 2010-03-21 07:16:43 +0000 | [diff] [blame] | 401 | .. versionadded:: 3.2 |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 402 | |
| 403 | |
| 404 | .. function:: iselement(element) |
| 405 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 406 | Checks if an object appears to be a valid element object. *element* is an |
| 407 | element instance. Returns a true value if this is an element object. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 408 | |
| 409 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 410 | .. function:: iterparse(source, events=None, parser=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 411 | |
| 412 | 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] | 413 | 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] | 414 | containing XML data. *events* is a sequence of events to report back. The |
Eli Bendersky | 604c4ff | 2012-03-16 08:41:30 +0200 | [diff] [blame] | 415 | supported events are the strings ``"start"``, ``"end"``, ``"start-ns"`` |
| 416 | and ``"end-ns"`` (the "ns" events are used to get detailed namespace |
| 417 | information). If *events* is omitted, only ``"end"`` events are reported. |
| 418 | *parser* is an optional parser instance. If not given, the standard |
Eli Bendersky | ca97fd3 | 2013-08-03 18:52:32 -0700 | [diff] [blame] | 419 | :class:`XMLParser` parser is used. *parser* can only use the default |
| 420 | :class:`TreeBuilder` as a target. Returns an :term:`iterator` providing |
Eli Bendersky | 604c4ff | 2012-03-16 08:41:30 +0200 | [diff] [blame] | 421 | ``(event, elem)`` pairs. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 422 | |
Eli Bendersky | ab2a76c | 2013-04-20 05:53:50 -0700 | [diff] [blame] | 423 | Note that while :func:`iterparse` builds the tree incrementally, it issues |
| 424 | blocking reads on *source* (or the file it names). As such, it's unsuitable |
| 425 | for asynchronous applications where blocking reads can't be made. For fully |
Eli Bendersky | 10e0af8 | 2013-04-20 05:54:29 -0700 | [diff] [blame] | 426 | asynchronous parsing, see :class:`IncrementalParser`. |
Eli Bendersky | ab2a76c | 2013-04-20 05:53:50 -0700 | [diff] [blame] | 427 | |
Benjamin Peterson | 75edad0 | 2009-01-01 15:05:06 +0000 | [diff] [blame] | 428 | .. note:: |
| 429 | |
| 430 | :func:`iterparse` only guarantees that it has seen the ">" |
| 431 | character of a starting tag when it emits a "start" event, so the |
| 432 | attributes are defined, but the contents of the text and tail attributes |
| 433 | are undefined at that point. The same applies to the element children; |
| 434 | they may or may not be present. |
| 435 | |
| 436 | If you need a fully populated element, look for "end" events instead. |
| 437 | |
Georg Brandl | 7f01a13 | 2009-09-16 15:58:14 +0000 | [diff] [blame] | 438 | .. function:: parse(source, parser=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 439 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 440 | Parses an XML section into an element tree. *source* is a filename or file |
| 441 | object containing XML data. *parser* is an optional parser instance. If |
| 442 | not given, the standard :class:`XMLParser` parser is used. Returns an |
| 443 | :class:`ElementTree` instance. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 444 | |
| 445 | |
Georg Brandl | 7f01a13 | 2009-09-16 15:58:14 +0000 | [diff] [blame] | 446 | .. function:: ProcessingInstruction(target, text=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 447 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 448 | PI element factory. This factory function creates a special element that |
| 449 | will be serialized as an XML processing instruction. *target* is a string |
| 450 | containing the PI target. *text* is a string containing the PI contents, if |
| 451 | given. Returns an element instance, representing a processing instruction. |
| 452 | |
| 453 | |
| 454 | .. function:: register_namespace(prefix, uri) |
| 455 | |
| 456 | Registers a namespace prefix. The registry is global, and any existing |
| 457 | mapping for either the given prefix or the namespace URI will be removed. |
| 458 | *prefix* is a namespace prefix. *uri* is a namespace uri. Tags and |
| 459 | attributes in this namespace will be serialized with the given prefix, if at |
| 460 | all possible. |
| 461 | |
Ezio Melotti | f8754a6 | 2010-03-21 07:16:43 +0000 | [diff] [blame] | 462 | .. versionadded:: 3.2 |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 463 | |
| 464 | |
Georg Brandl | 7f01a13 | 2009-09-16 15:58:14 +0000 | [diff] [blame] | 465 | .. function:: SubElement(parent, tag, attrib={}, **extra) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 466 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 467 | Subelement factory. This function creates an element instance, and appends |
| 468 | it to an existing element. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 469 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 470 | The element name, attribute names, and attribute values can be either |
| 471 | bytestrings or Unicode strings. *parent* is the parent element. *tag* is |
| 472 | the subelement name. *attrib* is an optional dictionary, containing element |
| 473 | attributes. *extra* contains additional attributes, given as keyword |
| 474 | arguments. Returns an element instance. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 475 | |
| 476 | |
Serhiy Storchaka | 9e189f0 | 2013-01-13 22:24:27 +0200 | [diff] [blame] | 477 | .. function:: tostring(element, encoding="us-ascii", method="xml", *, \ |
Eli Bendersky | a9a2ef5 | 2013-01-13 06:04:43 -0800 | [diff] [blame] | 478 | short_empty_elements=True) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 479 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 480 | Generates a string representation of an XML element, including all |
Florent Xicluna | dddd5e9 | 2010-03-14 01:28:07 +0000 | [diff] [blame] | 481 | subelements. *element* is an :class:`Element` instance. *encoding* [1]_ is |
Florent Xicluna | c17f172 | 2010-08-08 19:48:29 +0000 | [diff] [blame] | 482 | the output encoding (default is US-ASCII). Use ``encoding="unicode"`` to |
Eli Bendersky | 831893a | 2012-10-09 07:18:16 -0700 | [diff] [blame] | 483 | generate a Unicode string (otherwise, a bytestring is generated). *method* |
| 484 | is either ``"xml"``, ``"html"`` or ``"text"`` (default is ``"xml"``). |
Eli Bendersky | a9a2ef5 | 2013-01-13 06:04:43 -0800 | [diff] [blame] | 485 | *short_empty_elements* has the same meaning as in :meth:`ElementTree.write`. |
Eli Bendersky | 831893a | 2012-10-09 07:18:16 -0700 | [diff] [blame] | 486 | Returns an (optionally) encoded string containing the XML data. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 487 | |
Eli Bendersky | a9a2ef5 | 2013-01-13 06:04:43 -0800 | [diff] [blame] | 488 | .. versionadded:: 3.4 |
| 489 | The *short_empty_elements* parameter. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 490 | |
Eli Bendersky | a9a2ef5 | 2013-01-13 06:04:43 -0800 | [diff] [blame] | 491 | |
Serhiy Storchaka | 9e189f0 | 2013-01-13 22:24:27 +0200 | [diff] [blame] | 492 | .. function:: tostringlist(element, encoding="us-ascii", method="xml", *, \ |
Eli Bendersky | a9a2ef5 | 2013-01-13 06:04:43 -0800 | [diff] [blame] | 493 | short_empty_elements=True) |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 494 | |
| 495 | Generates a string representation of an XML element, including all |
Florent Xicluna | dddd5e9 | 2010-03-14 01:28:07 +0000 | [diff] [blame] | 496 | subelements. *element* is an :class:`Element` instance. *encoding* [1]_ is |
Florent Xicluna | c17f172 | 2010-08-08 19:48:29 +0000 | [diff] [blame] | 497 | the output encoding (default is US-ASCII). Use ``encoding="unicode"`` to |
Eli Bendersky | 831893a | 2012-10-09 07:18:16 -0700 | [diff] [blame] | 498 | generate a Unicode string (otherwise, a bytestring is generated). *method* |
| 499 | is either ``"xml"``, ``"html"`` or ``"text"`` (default is ``"xml"``). |
Eli Bendersky | a9a2ef5 | 2013-01-13 06:04:43 -0800 | [diff] [blame] | 500 | *short_empty_elements* has the same meaning as in :meth:`ElementTree.write`. |
Eli Bendersky | 831893a | 2012-10-09 07:18:16 -0700 | [diff] [blame] | 501 | Returns a list of (optionally) encoded strings containing the XML data. |
| 502 | It does not guarantee any specific sequence, except that |
| 503 | ``"".join(tostringlist(element)) == tostring(element)``. |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 504 | |
Ezio Melotti | f8754a6 | 2010-03-21 07:16:43 +0000 | [diff] [blame] | 505 | .. versionadded:: 3.2 |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 506 | |
Eli Bendersky | a9a2ef5 | 2013-01-13 06:04:43 -0800 | [diff] [blame] | 507 | .. versionadded:: 3.4 |
| 508 | The *short_empty_elements* parameter. |
| 509 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 510 | |
| 511 | .. function:: XML(text, parser=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 512 | |
| 513 | 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] | 514 | embed "XML literals" in Python code. *text* is a string containing XML |
| 515 | data. *parser* is an optional parser instance. If not given, the standard |
| 516 | :class:`XMLParser` parser is used. Returns an :class:`Element` instance. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 517 | |
| 518 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 519 | .. function:: XMLID(text, parser=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 520 | |
| 521 | 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] | 522 | which maps from element id:s to elements. *text* is a string containing XML |
| 523 | data. *parser* is an optional parser instance. If not given, the standard |
| 524 | :class:`XMLParser` parser is used. Returns a tuple containing an |
| 525 | :class:`Element` instance and a dictionary. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 526 | |
| 527 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 528 | .. _elementtree-element-objects: |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 529 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 530 | Element Objects |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 531 | ^^^^^^^^^^^^^^^ |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 532 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 533 | .. class:: Element(tag, attrib={}, **extra) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 534 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 535 | Element class. This class defines the Element interface, and provides a |
| 536 | reference implementation of this interface. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 537 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 538 | The element name, attribute names, and attribute values can be either |
| 539 | bytestrings or Unicode strings. *tag* is the element name. *attrib* is |
| 540 | an optional dictionary, containing element attributes. *extra* contains |
| 541 | additional attributes, given as keyword arguments. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 542 | |
| 543 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 544 | .. attribute:: tag |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 545 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 546 | A string identifying what kind of data this element represents (the |
| 547 | element type, in other words). |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 548 | |
| 549 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 550 | .. attribute:: text |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 551 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 552 | The *text* attribute can be used to hold additional data associated with |
| 553 | the element. As the name implies this attribute is usually a string but |
| 554 | may be any application-specific object. If the element is created from |
| 555 | an XML file the attribute will contain any text found between the element |
| 556 | tags. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 557 | |
| 558 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 559 | .. attribute:: tail |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 560 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 561 | The *tail* attribute can be used to hold additional data associated with |
| 562 | the element. This attribute is usually a string but may be any |
| 563 | application-specific object. If the element is created from an XML file |
| 564 | the attribute will contain any text found after the element's end tag and |
| 565 | before the next tag. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 566 | |
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 | .. attribute:: attrib |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 569 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 570 | A dictionary containing the element's attributes. Note that while the |
| 571 | *attrib* value is always a real mutable Python dictionary, an ElementTree |
| 572 | implementation may choose to use another internal representation, and |
| 573 | create the dictionary only if someone asks for it. To take advantage of |
| 574 | such implementations, use the dictionary methods below whenever possible. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 575 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 576 | The following dictionary-like methods work on the element attributes. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 577 | |
| 578 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 579 | .. method:: clear() |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 580 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 581 | Resets an element. This function removes all subelements, clears all |
Eli Bendersky | 323a43a | 2012-10-09 06:46:33 -0700 | [diff] [blame] | 582 | attributes, and sets the text and tail attributes to ``None``. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 583 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 584 | |
| 585 | .. method:: get(key, default=None) |
| 586 | |
| 587 | Gets the element attribute named *key*. |
| 588 | |
| 589 | Returns the attribute value, or *default* if the attribute was not found. |
| 590 | |
| 591 | |
| 592 | .. method:: items() |
| 593 | |
| 594 | Returns the element attributes as a sequence of (name, value) pairs. The |
| 595 | attributes are returned in an arbitrary order. |
| 596 | |
| 597 | |
| 598 | .. method:: keys() |
| 599 | |
| 600 | Returns the elements attribute names as a list. The names are returned |
| 601 | in an arbitrary order. |
| 602 | |
| 603 | |
| 604 | .. method:: set(key, value) |
| 605 | |
| 606 | Set the attribute *key* on the element to *value*. |
| 607 | |
| 608 | The following methods work on the element's children (subelements). |
| 609 | |
| 610 | |
| 611 | .. method:: append(subelement) |
| 612 | |
Eli Bendersky | 396e8fc | 2012-03-23 14:24:20 +0200 | [diff] [blame] | 613 | Adds the element *subelement* to the end of this element's internal list |
| 614 | of subelements. Raises :exc:`TypeError` if *subelement* is not an |
| 615 | :class:`Element`. |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 616 | |
| 617 | |
| 618 | .. method:: extend(subelements) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 619 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 620 | Appends *subelements* from a sequence object with zero or more elements. |
Eli Bendersky | 396e8fc | 2012-03-23 14:24:20 +0200 | [diff] [blame] | 621 | Raises :exc:`TypeError` if a subelement is not an :class:`Element`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 622 | |
Ezio Melotti | f8754a6 | 2010-03-21 07:16:43 +0000 | [diff] [blame] | 623 | .. versionadded:: 3.2 |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 624 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 625 | |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 626 | .. method:: find(match, namespaces=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 627 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 628 | Finds the first subelement matching *match*. *match* may be a tag name |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 629 | or a :ref:`path <elementtree-xpath>`. Returns an element instance |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 630 | or ``None``. *namespaces* is an optional mapping from namespace prefix |
| 631 | to full name. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 632 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 633 | |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 634 | .. method:: findall(match, namespaces=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 635 | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 636 | Finds all matching subelements, by tag name or |
| 637 | :ref:`path <elementtree-xpath>`. Returns a list containing all matching |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 638 | elements in document order. *namespaces* is an optional mapping from |
| 639 | namespace prefix to full name. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 640 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 641 | |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 642 | .. method:: findtext(match, default=None, namespaces=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 643 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 644 | Finds text for the first subelement matching *match*. *match* may be |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 645 | a tag name or a :ref:`path <elementtree-xpath>`. Returns the text content |
| 646 | of the first matching element, or *default* if no element was found. |
| 647 | 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] | 648 | is returned. *namespaces* is an optional mapping from namespace prefix |
| 649 | to full name. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 650 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 651 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 652 | .. method:: getchildren() |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 653 | |
Georg Brandl | 67b21b7 | 2010-08-17 15:07:14 +0000 | [diff] [blame] | 654 | .. deprecated:: 3.2 |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 655 | Use ``list(elem)`` or iteration. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 656 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 657 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 658 | .. method:: getiterator(tag=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 659 | |
Georg Brandl | 67b21b7 | 2010-08-17 15:07:14 +0000 | [diff] [blame] | 660 | .. deprecated:: 3.2 |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 661 | Use method :meth:`Element.iter` instead. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 662 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 663 | |
Eli Bendersky | 396e8fc | 2012-03-23 14:24:20 +0200 | [diff] [blame] | 664 | .. method:: insert(index, subelement) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 665 | |
Eli Bendersky | 396e8fc | 2012-03-23 14:24:20 +0200 | [diff] [blame] | 666 | Inserts *subelement* at the given position in this element. Raises |
| 667 | :exc:`TypeError` if *subelement* is not an :class:`Element`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 668 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 669 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 670 | .. method:: iter(tag=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 671 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 672 | Creates a tree :term:`iterator` with the current element as the root. |
| 673 | The iterator iterates over this element and all elements below it, in |
| 674 | document (depth first) order. If *tag* is not ``None`` or ``'*'``, only |
| 675 | elements whose tag equals *tag* are returned from the iterator. If the |
| 676 | tree structure is modified during iteration, the result is undefined. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 677 | |
Ezio Melotti | 138fc89 | 2011-10-10 00:02:03 +0300 | [diff] [blame] | 678 | .. versionadded:: 3.2 |
| 679 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 680 | |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 681 | .. method:: iterfind(match, namespaces=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 682 | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 683 | Finds all matching subelements, by tag name or |
| 684 | :ref:`path <elementtree-xpath>`. Returns an iterable yielding all |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 685 | matching elements in document order. *namespaces* is an optional mapping |
| 686 | from namespace prefix to full name. |
| 687 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 688 | |
Ezio Melotti | f8754a6 | 2010-03-21 07:16:43 +0000 | [diff] [blame] | 689 | .. versionadded:: 3.2 |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 690 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 691 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 692 | .. method:: itertext() |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 693 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 694 | Creates a text iterator. The iterator loops over this element and all |
| 695 | subelements, in document order, and returns all inner text. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 696 | |
Ezio Melotti | f8754a6 | 2010-03-21 07:16:43 +0000 | [diff] [blame] | 697 | .. versionadded:: 3.2 |
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:: makeelement(tag, attrib) |
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 | Creates a new element object of the same type as this element. Do not |
| 703 | call this method, use the :func:`SubElement` factory function instead. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 704 | |
| 705 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 706 | .. method:: remove(subelement) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 707 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 708 | Removes *subelement* from the element. Unlike the find\* methods this |
| 709 | method compares elements based on the instance identity, not on tag value |
| 710 | or contents. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 711 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 712 | :class:`Element` objects also support the following sequence type methods |
| 713 | for working with subelements: :meth:`__delitem__`, :meth:`__getitem__`, |
| 714 | :meth:`__setitem__`, :meth:`__len__`. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 715 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 716 | Caution: Elements with no subelements will test as ``False``. This behavior |
| 717 | will change in future versions. Use specific ``len(elem)`` or ``elem is |
| 718 | None`` test instead. :: |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 719 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 720 | element = root.find('foo') |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 721 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 722 | if not element: # careful! |
| 723 | print("element not found, or element has no subelements") |
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 | if element is None: |
| 726 | print("element not found") |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 727 | |
| 728 | |
| 729 | .. _elementtree-elementtree-objects: |
| 730 | |
| 731 | ElementTree Objects |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 732 | ^^^^^^^^^^^^^^^^^^^ |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 733 | |
| 734 | |
Georg Brandl | 7f01a13 | 2009-09-16 15:58:14 +0000 | [diff] [blame] | 735 | .. class:: ElementTree(element=None, file=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 736 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 737 | ElementTree wrapper class. This class represents an entire element |
| 738 | hierarchy, and adds some extra support for serialization to and from |
| 739 | standard XML. |
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 | *element* is the root element. The tree is initialized with the contents |
| 742 | of the XML *file* if given. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 743 | |
| 744 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 745 | .. method:: _setroot(element) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 746 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 747 | Replaces the root element for this tree. This discards the current |
| 748 | 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] | 749 | care. *element* is an element instance. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 750 | |
| 751 | |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 752 | .. method:: find(match, namespaces=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 753 | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 754 | Same as :meth:`Element.find`, starting at the root of the tree. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 755 | |
| 756 | |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 757 | .. method:: findall(match, namespaces=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 758 | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 759 | Same as :meth:`Element.findall`, starting at the root of the tree. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 760 | |
| 761 | |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 762 | .. method:: findtext(match, default=None, namespaces=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 763 | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 764 | Same as :meth:`Element.findtext`, starting at the root of the tree. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 765 | |
| 766 | |
Georg Brandl | 7f01a13 | 2009-09-16 15:58:14 +0000 | [diff] [blame] | 767 | .. method:: getiterator(tag=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 768 | |
Georg Brandl | 67b21b7 | 2010-08-17 15:07:14 +0000 | [diff] [blame] | 769 | .. deprecated:: 3.2 |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 770 | Use method :meth:`ElementTree.iter` instead. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 771 | |
| 772 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 773 | .. method:: getroot() |
Florent Xicluna | c17f172 | 2010-08-08 19:48:29 +0000 | [diff] [blame] | 774 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 775 | Returns the root element for this tree. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 776 | |
| 777 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 778 | .. method:: iter(tag=None) |
| 779 | |
| 780 | Creates and returns a tree iterator for the root element. The iterator |
| 781 | loops over all elements in this tree, in section order. *tag* is the tag |
| 782 | to look for (default is to return all elements) |
| 783 | |
| 784 | |
Eli Bendersky | 737b173 | 2012-05-29 06:02:56 +0300 | [diff] [blame] | 785 | .. method:: iterfind(match, namespaces=None) |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 786 | |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 787 | Same as :meth:`Element.iterfind`, starting at the root of the tree. |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 788 | |
Ezio Melotti | f8754a6 | 2010-03-21 07:16:43 +0000 | [diff] [blame] | 789 | .. versionadded:: 3.2 |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 790 | |
| 791 | |
Georg Brandl | 7f01a13 | 2009-09-16 15:58:14 +0000 | [diff] [blame] | 792 | .. method:: parse(source, parser=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 793 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 794 | 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] | 795 | name or :term:`file object`. *parser* is an optional parser instance. |
Eli Bendersky | 52467b1 | 2012-06-01 07:13:08 +0300 | [diff] [blame] | 796 | If not given, the standard :class:`XMLParser` parser is used. Returns the |
| 797 | section root element. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 798 | |
| 799 | |
Eli Bendersky | f96cf91 | 2012-07-15 06:19:44 +0300 | [diff] [blame] | 800 | .. method:: write(file, encoding="us-ascii", xml_declaration=None, \ |
Serhiy Storchaka | 9e189f0 | 2013-01-13 22:24:27 +0200 | [diff] [blame] | 801 | default_namespace=None, method="xml", *, \ |
Eli Bendersky | e9af827 | 2013-01-13 06:27:51 -0800 | [diff] [blame] | 802 | short_empty_elements=True) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 803 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 804 | 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] | 805 | :term:`file object` opened for writing. *encoding* [1]_ is the output |
| 806 | encoding (default is US-ASCII). |
| 807 | *xml_declaration* controls if an XML declaration should be added to the |
| 808 | file. Use ``False`` for never, ``True`` for always, ``None`` |
| 809 | 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] | 810 | *default_namespace* sets the default XML namespace (for "xmlns"). |
Eli Bendersky | f96cf91 | 2012-07-15 06:19:44 +0300 | [diff] [blame] | 811 | *method* is either ``"xml"``, ``"html"`` or ``"text"`` (default is |
| 812 | ``"xml"``). |
Eli Bendersky | a9a2ef5 | 2013-01-13 06:04:43 -0800 | [diff] [blame] | 813 | The keyword-only *short_empty_elements* parameter controls the formatting |
| 814 | of elements that contain no content. If *True* (the default), they are |
| 815 | emitted as a single self-closed tag, otherwise they are emitted as a pair |
| 816 | of start/end tags. |
Eli Bendersky | f96cf91 | 2012-07-15 06:19:44 +0300 | [diff] [blame] | 817 | |
| 818 | The output is either a string (:class:`str`) or binary (:class:`bytes`). |
| 819 | This is controlled by the *encoding* argument. If *encoding* is |
| 820 | ``"unicode"``, the output is a string; otherwise, it's binary. Note that |
| 821 | this may conflict with the type of *file* if it's an open |
| 822 | :term:`file object`; make sure you do not try to write a string to a |
| 823 | binary stream and vice versa. |
| 824 | |
Eli Bendersky | a9a2ef5 | 2013-01-13 06:04:43 -0800 | [diff] [blame] | 825 | .. versionadded:: 3.4 |
| 826 | The *short_empty_elements* parameter. |
| 827 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 828 | |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 829 | This is the XML file that is going to be manipulated:: |
| 830 | |
| 831 | <html> |
| 832 | <head> |
| 833 | <title>Example page</title> |
| 834 | </head> |
| 835 | <body> |
Georg Brandl | 48310cd | 2009-01-03 21:18:54 +0000 | [diff] [blame] | 836 | <p>Moved to <a href="http://example.org/">example.org</a> |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 837 | or <a href="http://example.com/">example.com</a>.</p> |
| 838 | </body> |
| 839 | </html> |
| 840 | |
| 841 | Example of changing the attribute "target" of every link in first paragraph:: |
| 842 | |
| 843 | >>> from xml.etree.ElementTree import ElementTree |
| 844 | >>> tree = ElementTree() |
| 845 | >>> tree.parse("index.xhtml") |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 846 | <Element 'html' at 0xb77e6fac> |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 847 | >>> p = tree.find("body/p") # Finds first occurrence of tag p in body |
| 848 | >>> p |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 849 | <Element 'p' at 0xb77ec26c> |
| 850 | >>> links = list(p.iter("a")) # Returns list of all links |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 851 | >>> links |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 852 | [<Element 'a' at 0xb77ec2ac>, <Element 'a' at 0xb77ec1cc>] |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 853 | >>> for i in links: # Iterates through all found links |
| 854 | ... i.attrib["target"] = "blank" |
| 855 | >>> tree.write("output.xhtml") |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 856 | |
| 857 | .. _elementtree-qname-objects: |
| 858 | |
| 859 | QName Objects |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 860 | ^^^^^^^^^^^^^ |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 861 | |
| 862 | |
Georg Brandl | 7f01a13 | 2009-09-16 15:58:14 +0000 | [diff] [blame] | 863 | .. class:: QName(text_or_uri, tag=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 864 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 865 | QName wrapper. This can be used to wrap a QName attribute value, in order |
| 866 | to get proper namespace handling on output. *text_or_uri* is a string |
| 867 | containing the QName value, in the form {uri}local, or, if the tag argument |
| 868 | is given, the URI part of a QName. If *tag* is given, the first argument is |
| 869 | interpreted as an URI, and this argument is interpreted as a local name. |
| 870 | :class:`QName` instances are opaque. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 871 | |
| 872 | |
Antoine Pitrou | 5b235d0 | 2013-04-18 19:37:06 +0200 | [diff] [blame] | 873 | IncrementalParser Objects |
| 874 | ^^^^^^^^^^^^^^^^^^^^^^^^^ |
| 875 | |
Antoine Pitrou | 5b235d0 | 2013-04-18 19:37:06 +0200 | [diff] [blame] | 876 | .. class:: IncrementalParser(events=None, parser=None) |
| 877 | |
| 878 | An incremental, event-driven parser suitable for non-blocking applications. |
Eli Bendersky | fb62544 | 2013-05-19 09:09:24 -0700 | [diff] [blame] | 879 | *events* is a sequence of events to report back. The supported events are |
| 880 | the strings ``"start"``, ``"end"``, ``"start-ns"`` and ``"end-ns"`` (the "ns" |
Antoine Pitrou | 5b235d0 | 2013-04-18 19:37:06 +0200 | [diff] [blame] | 881 | events are used to get detailed namespace information). If *events* is |
| 882 | omitted, only ``"end"`` events are reported. *parser* is an optional |
| 883 | parser instance. If not given, the standard :class:`XMLParser` parser is |
Eli Bendersky | c4216ab | 2013-08-03 18:55:10 -0700 | [diff] [blame] | 884 | used. *parser* can only use the default :class:`TreeBuilder` as a target. |
Antoine Pitrou | 5b235d0 | 2013-04-18 19:37:06 +0200 | [diff] [blame] | 885 | |
| 886 | .. method:: data_received(data) |
| 887 | |
| 888 | Feed the given bytes data to the incremental parser. |
| 889 | |
| 890 | .. method:: eof_received() |
| 891 | |
| 892 | Signal the incremental parser that the data stream is terminated. |
| 893 | |
| 894 | .. method:: events() |
| 895 | |
| 896 | Iterate over the events which have been encountered in the data fed |
| 897 | to the parser. This method yields ``(event, elem)`` pairs, where |
| 898 | *event* is a string representing the type of event (e.g. ``"end"``) |
Eli Bendersky | 3bdead1 | 2013-04-20 09:06:27 -0700 | [diff] [blame] | 899 | and *elem* is the encountered :class:`Element` object. Events |
| 900 | provided in a previous call to :meth:`events` will not be yielded |
| 901 | again. |
Antoine Pitrou | 5b235d0 | 2013-04-18 19:37:06 +0200 | [diff] [blame] | 902 | |
| 903 | .. note:: |
| 904 | |
| 905 | :class:`IncrementalParser` only guarantees that it has seen the ">" |
| 906 | character of a starting tag when it emits a "start" event, so the |
| 907 | attributes are defined, but the contents of the text and tail attributes |
| 908 | are undefined at that point. The same applies to the element children; |
| 909 | they may or may not be present. |
| 910 | |
| 911 | If you need a fully populated element, look for "end" events instead. |
| 912 | |
| 913 | .. versionadded:: 3.4 |
| 914 | |
| 915 | |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 916 | .. _elementtree-treebuilder-objects: |
| 917 | |
| 918 | TreeBuilder Objects |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 919 | ^^^^^^^^^^^^^^^^^^^ |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 920 | |
| 921 | |
Georg Brandl | 7f01a13 | 2009-09-16 15:58:14 +0000 | [diff] [blame] | 922 | .. class:: TreeBuilder(element_factory=None) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 923 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 924 | Generic element structure builder. This builder converts a sequence of |
| 925 | start, data, and end method calls to a well-formed element structure. You |
| 926 | 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] | 927 | or a parser for some other XML-like format. *element_factory*, when given, |
| 928 | must be a callable accepting two positional arguments: a tag and |
| 929 | 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] | 930 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 931 | .. method:: close() |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 932 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 933 | Flushes the builder buffers, and returns the toplevel document |
| 934 | element. Returns an :class:`Element` instance. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 935 | |
| 936 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 937 | .. method:: data(data) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 938 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 939 | Adds text to the current element. *data* is a string. This should be |
| 940 | either a bytestring, or a Unicode string. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 941 | |
| 942 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 943 | .. method:: end(tag) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 944 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 945 | Closes the current element. *tag* is the element name. Returns the |
| 946 | closed element. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 947 | |
| 948 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 949 | .. method:: start(tag, attrs) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 950 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 951 | Opens a new element. *tag* is the element name. *attrs* is a dictionary |
| 952 | containing element attributes. Returns the opened element. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 953 | |
| 954 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 955 | In addition, a custom :class:`TreeBuilder` object can provide the |
| 956 | following method: |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 957 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 958 | .. method:: doctype(name, pubid, system) |
| 959 | |
| 960 | Handles a doctype declaration. *name* is the doctype name. *pubid* is |
| 961 | the public identifier. *system* is the system identifier. This method |
| 962 | does not exist on the default :class:`TreeBuilder` class. |
| 963 | |
Ezio Melotti | f8754a6 | 2010-03-21 07:16:43 +0000 | [diff] [blame] | 964 | .. versionadded:: 3.2 |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 965 | |
| 966 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 967 | .. _elementtree-xmlparser-objects: |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 968 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 969 | XMLParser Objects |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 970 | ^^^^^^^^^^^^^^^^^ |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 971 | |
| 972 | |
| 973 | .. class:: XMLParser(html=0, target=None, encoding=None) |
| 974 | |
| 975 | :class:`Element` structure builder for XML source data, based on the expat |
| 976 | parser. *html* are predefined HTML entities. This flag is not supported by |
| 977 | the current implementation. *target* is the target object. If omitted, the |
Eli Bendersky | 1bf2394 | 2012-06-01 07:15:00 +0300 | [diff] [blame] | 978 | builder uses an instance of the standard :class:`TreeBuilder` class. |
Eli Bendersky | 52467b1 | 2012-06-01 07:13:08 +0300 | [diff] [blame] | 979 | *encoding* [1]_ is optional. If given, the value overrides the encoding |
| 980 | specified in the XML file. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 981 | |
| 982 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 983 | .. method:: close() |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 984 | |
Eli Bendersky | bfd7837 | 2013-08-24 15:11:44 -0700 | [diff] [blame^] | 985 | Finishes feeding data to the parser. Returns the result of calling the |
| 986 | `close` method of the *target* passed during construction; by default, |
| 987 | this is the toplevel document element. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 988 | |
| 989 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 990 | .. method:: doctype(name, pubid, system) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 991 | |
Georg Brandl | 67b21b7 | 2010-08-17 15:07:14 +0000 | [diff] [blame] | 992 | .. deprecated:: 3.2 |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 993 | Define the :meth:`TreeBuilder.doctype` method on a custom TreeBuilder |
| 994 | target. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 995 | |
| 996 | |
Benjamin Peterson | e41251e | 2008-04-25 01:59:09 +0000 | [diff] [blame] | 997 | .. method:: feed(data) |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 998 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 999 | Feeds data to the parser. *data* is encoded data. |
Georg Brandl | 116aa62 | 2007-08-15 14:28:22 +0000 | [diff] [blame] | 1000 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 1001 | :meth:`XMLParser.feed` calls *target*\'s :meth:`start` method |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 1002 | for each opening tag, its :meth:`end` method for each closing tag, |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 1003 | and data is processed by method :meth:`data`. :meth:`XMLParser.close` |
Georg Brandl | 48310cd | 2009-01-03 21:18:54 +0000 | [diff] [blame] | 1004 | calls *target*\'s method :meth:`close`. |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 1005 | :class:`XMLParser` can be used not only for building a tree structure. |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 1006 | This is an example of counting the maximum depth of an XML file:: |
| 1007 | |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 1008 | >>> from xml.etree.ElementTree import XMLParser |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 1009 | >>> class MaxDepth: # The target object of the parser |
| 1010 | ... maxDepth = 0 |
| 1011 | ... depth = 0 |
| 1012 | ... def start(self, tag, attrib): # Called for each opening tag. |
Georg Brandl | 48310cd | 2009-01-03 21:18:54 +0000 | [diff] [blame] | 1013 | ... self.depth += 1 |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 1014 | ... if self.depth > self.maxDepth: |
| 1015 | ... self.maxDepth = self.depth |
| 1016 | ... def end(self, tag): # Called for each closing tag. |
| 1017 | ... self.depth -= 1 |
Georg Brandl | 48310cd | 2009-01-03 21:18:54 +0000 | [diff] [blame] | 1018 | ... def data(self, data): |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 1019 | ... pass # We do not need to do anything with data. |
| 1020 | ... def close(self): # Called when all data has been parsed. |
| 1021 | ... return self.maxDepth |
Georg Brandl | 48310cd | 2009-01-03 21:18:54 +0000 | [diff] [blame] | 1022 | ... |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 1023 | >>> target = MaxDepth() |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 1024 | >>> parser = XMLParser(target=target) |
Christian Heimes | d8654cf | 2007-12-02 15:22:16 +0000 | [diff] [blame] | 1025 | >>> exampleXml = """ |
| 1026 | ... <a> |
| 1027 | ... <b> |
| 1028 | ... </b> |
| 1029 | ... <b> |
| 1030 | ... <c> |
| 1031 | ... <d> |
| 1032 | ... </d> |
| 1033 | ... </c> |
| 1034 | ... </b> |
| 1035 | ... </a>""" |
| 1036 | >>> parser.feed(exampleXml) |
| 1037 | >>> parser.close() |
| 1038 | 4 |
Christian Heimes | b186d00 | 2008-03-18 15:15:01 +0000 | [diff] [blame] | 1039 | |
Eli Bendersky | 5b77d81 | 2012-03-16 08:20:05 +0200 | [diff] [blame] | 1040 | Exceptions |
Eli Bendersky | 3a4875e | 2012-03-26 20:43:32 +0200 | [diff] [blame] | 1041 | ^^^^^^^^^^ |
Eli Bendersky | 5b77d81 | 2012-03-16 08:20:05 +0200 | [diff] [blame] | 1042 | |
| 1043 | .. class:: ParseError |
| 1044 | |
| 1045 | XML parse error, raised by the various parsing methods in this module when |
| 1046 | parsing fails. The string representation of an instance of this exception |
| 1047 | will contain a user-friendly error message. In addition, it will have |
| 1048 | the following attributes available: |
| 1049 | |
| 1050 | .. attribute:: code |
| 1051 | |
| 1052 | A numeric error code from the expat parser. See the documentation of |
| 1053 | :mod:`xml.parsers.expat` for the list of error codes and their meanings. |
| 1054 | |
| 1055 | .. attribute:: position |
| 1056 | |
| 1057 | A tuple of *line*, *column* numbers, specifying where the error occurred. |
Christian Heimes | b186d00 | 2008-03-18 15:15:01 +0000 | [diff] [blame] | 1058 | |
| 1059 | .. rubric:: Footnotes |
| 1060 | |
| 1061 | .. [#] The encoding string included in XML output should conform to the |
Florent Xicluna | f15351d | 2010-03-13 23:24:31 +0000 | [diff] [blame] | 1062 | appropriate standards. For example, "UTF-8" is valid, but "UTF8" is |
| 1063 | 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] | 1064 | and http://www.iana.org/assignments/character-sets. |