FM / library

/usr/share/doc/python3-docs/html/_sources/library/

/usr/share/doc/python3-docs/html/_sources/library

Name	Size	Mode	Actions
2to3.rst.txt	15898	0644	edit dl rm
abc.rst.txt	11805	0644	edit dl rm
aifc.rst.txt	7503	0644	edit dl rm
allos.rst.txt	678	0644	edit dl rm
archiving.rst.txt	440	0644	edit dl rm
argparse.rst.txt	77480	0644	edit dl rm
array.rst.txt	10812	0644	edit dl rm
ast.rst.txt	10159	0644	edit dl rm
asynchat.rst.txt	8528	0644	edit dl rm
asyncio-dev.rst.txt	13398	0644	edit dl rm
asyncio-eventloop.rst.txt	33701	0644	edit dl rm
asyncio-eventloops.rst.txt	7660	0644	edit dl rm
asyncio-protocol.rst.txt	25170	0644	edit dl rm
asyncio-queue.rst.txt	4328	0644	edit dl rm
asyncio-stream.rst.txt	14363	0644	edit dl rm
asyncio-subprocess.rst.txt	15544	0644	edit dl rm
asyncio-sync.rst.txt	9078	0644	edit dl rm
asyncio-task.rst.txt	25406	0644	edit dl rm
asyncio.rst.txt	2272	0644	edit dl rm
asyncore.rst.txt	13624	0644	edit dl rm
atexit.rst.txt	3669	0644	edit dl rm
audioop.rst.txt	10712	0644	edit dl rm
base64.rst.txt	10371	0644	edit dl rm
bdb.rst.txt	12985	0644	edit dl rm
binary.rst.txt	654	0644	edit dl rm
binascii.rst.txt	6539	0644	edit dl rm
binhex.rst.txt	1709	0644	edit dl rm
bisect.rst.txt	5398	0644	edit dl rm
builtins.rst.txt	1465	0644	edit dl rm
bz2.rst.txt	8825	0644	edit dl rm
calendar.rst.txt	10988	0644	edit dl rm
cgi.rst.txt	22650	0644	edit dl rm
cgitb.rst.txt	2918	0644	edit dl rm
chunk.rst.txt	5094	0644	edit dl rm
cmath.rst.txt	9326	0644	edit dl rm
cmd.rst.txt	13795	0644	edit dl rm
code.rst.txt	7817	0644	edit dl rm
codecs.rst.txt	75564	0644	edit dl rm
codeop.rst.txt	3021	0644	edit dl rm
collections.abc.rst.txt	12861	0644	edit dl rm
collections.rst.txt	46063	0644	edit dl rm
colorsys.rst.txt	1820	0644	edit dl rm
compileall.rst.txt	8975	0644	edit dl rm
concurrency.rst.txt	673	0644	edit dl rm
concurrent.futures.rst.txt	16910	0644	edit dl rm
concurrent.rst.txt	171	0644	edit dl rm
configparser.rst.txt	48756	0644	edit dl rm
constants.rst.txt	3331	0644	edit dl rm
contextlib.rst.txt	28175	0644	edit dl rm
copy.rst.txt	3378	0644	edit dl rm
copyreg.rst.txt	2182	0644	edit dl rm
crypt.rst.txt	5122	0644	edit dl rm
crypto.rst.txt	411	0644	edit dl rm
csv.rst.txt	19902	0644	edit dl rm
ctypes.rst.txt	88613	0644	edit dl rm
curses.ascii.rst.txt	8920	0644	edit dl rm
curses.panel.rst.txt	2764	0644	edit dl rm
curses.rst.txt	76397	0644	edit dl rm
custominterp.rst.txt	569	0644	edit dl rm
datatypes.rst.txt	751	0644	edit dl rm
datetime.rst.txt	90524	0644	edit dl rm
dbm.rst.txt	14293	0644	edit dl rm
debug.rst.txt	471	0644	edit dl rm
decimal.rst.txt	74869	0644	edit dl rm
development.rst.txt	704	0644	edit dl rm
difflib.rst.txt	29861	0644	edit dl rm
dis.rst.txt	32567	0644	edit dl rm
distribution.rst.txt	452	0644	edit dl rm
distutils.rst.txt	1974	0644	edit dl rm
doctest.rst.txt	71743	0644	edit dl rm
dummy_threading.rst.txt	784	0644	edit dl rm
email.charset.rst.txt	9293	0644	edit dl rm
email.compat32-message.rst.txt	33493	0644	edit dl rm
email.contentmanager.rst.txt	9112	0644	edit dl rm
email.encoders.rst.txt	2715	0644	edit dl rm
email.errors.rst.txt	4792	0644	edit dl rm
email.examples.rst.txt	1915	0644	edit dl rm
email.generator.rst.txt	13637	0644	edit dl rm
email.header.rst.txt	9188	0644	edit dl rm
email.headerregistry.rst.txt	17957	0644	edit dl rm
email.iterators.rst.txt	2795	0644	edit dl rm
email.message.rst.txt	33008	0644	edit dl rm
email.mime.rst.txt	11721	0644	edit dl rm
email.parser.rst.txt	14092	0644	edit dl rm
email.policy.rst.txt	27022	0644	edit dl rm
email.rst.txt	6785	0644	edit dl rm
email.util.rst.txt	9214	0644	edit dl rm
ensurepip.rst.txt	4987	0644	edit dl rm
enum.rst.txt	32751	0644	edit dl rm
errno.rst.txt	6811	0644	edit dl rm
exceptions.rst.txt	25570	0644	edit dl rm
faulthandler.rst.txt	6136	0644	edit dl rm
fcntl.rst.txt	7152	0644	edit dl rm
filecmp.rst.txt	5623	0644	edit dl rm
fileformats.rst.txt	287	0644	edit dl rm
fileinput.rst.txt	8051	0644	edit dl rm
filesys.rst.txt	961	0644	edit dl rm
fnmatch.rst.txt	3103	0644	edit dl rm
formatter.rst.txt	13242	0644	edit dl rm
fpectl.rst.txt	4180	0644	edit dl rm
fractions.rst.txt	6364	0644	edit dl rm
frameworks.rst.txt	391	0644	edit dl rm
ftplib.rst.txt	17552	0644	edit dl rm
functional.rst.txt	365	0644	edit dl rm
functions.rst.txt	71621	0644	edit dl rm
functools.rst.txt	18503	0644	edit dl rm
gc.rst.txt	9694	0644	edit dl rm
getopt.rst.txt	6557	0644	edit dl rm
getpass.rst.txt	1882	0644	edit dl rm
gettext.rst.txt	25588	0644	edit dl rm
glob.rst.txt	3508	0644	edit dl rm
grp.rst.txt	2417	0644	edit dl rm
gzip.rst.txt	8301	0644	edit dl rm
hashlib.rst.txt	26523	0644	edit dl rm
heapq.rst.txt	13402	0644	edit dl rm
hmac.rst.txt	4020	0644	edit dl rm
html.entities.rst.txt	1319	0644	edit dl rm
html.parser.rst.txt	11275	0644	edit dl rm
html.rst.txt	1304	0644	edit dl rm
http.client.rst.txt	18870	0644	edit dl rm
http.cookiejar.rst.txt	27832	0644	edit dl rm
http.cookies.rst.txt	8645	0644	edit dl rm
http.rst.txt	7096	0644	edit dl rm
http.server.rst.txt	17639	0644	edit dl rm
i18n.rst.txt	408	0644	edit dl rm
idle.rst.txt	25834	0644	edit dl rm
imaplib.rst.txt	20367	0644	edit dl rm
imghdr.rst.txt	2938	0644	edit dl rm
imp.rst.txt	15548	0644	edit dl rm
importlib.rst.txt	53563	0644	edit dl rm
index.rst.txt	2258	0644	edit dl rm
inspect.rst.txt	53928	0644	edit dl rm
internet.rst.txt	992	0644	edit dl rm
intro.rst.txt	2645	0644	edit dl rm
io.rst.txt	40328	0644	edit dl rm
ipaddress.rst.txt	32340	0644	edit dl rm
ipc.rst.txt	649	0644	edit dl rm
itertools.rst.txt	38459	0644	edit dl rm
json.rst.txt	27876	0644	edit dl rm
keyword.rst.txt	617	0644	edit dl rm
language.rst.txt	522	0644	edit dl rm
linecache.rst.txt	2408	0644	edit dl rm
locale.rst.txt	25470	0644	edit dl rm
logging.config.rst.txt	33886	0644	edit dl rm
logging.handlers.rst.txt	42497	0644	edit dl rm
logging.rst.txt	60479	0644	edit dl rm
lzma.rst.txt	17361	0644	edit dl rm
macpath.rst.txt	707	0644	edit dl rm
mailbox.rst.txt	63055	0644	edit dl rm
mailcap.rst.txt	3691	0644	edit dl rm
markup.rst.txt	679	0644	edit dl rm
marshal.rst.txt	4855	0644	edit dl rm
math.rst.txt	14375	0644	edit dl rm
mimetypes.rst.txt	9839	0644	edit dl rm
misc.rst.txt	247	0644	edit dl rm
mm.rst.txt	431	0644	edit dl rm
mmap.rst.txt	11232	0644	edit dl rm
modulefinder.rst.txt	3240	0644	edit dl rm
modules.rst.txt	355	0644	edit dl rm
msilib.rst.txt	18612	0644	edit dl rm
msvcrt.rst.txt	4392	0644	edit dl rm
multiprocessing.rst.txt	104494	0644	edit dl rm
netdata.rst.txt	339	0644	edit dl rm
netrc.rst.txt	3007	0644	edit dl rm
nis.rst.txt	1993	0644	edit dl rm
nntplib.rst.txt	21821	0644	edit dl rm
numbers.rst.txt	8089	0644	edit dl rm
numeric.rst.txt	696	0644	edit dl rm
operator.rst.txt	18989	0644	edit dl rm
optparse.rst.txt	76996	0644	edit dl rm
os.path.rst.txt	16419	0644	edit dl rm
os.rst.txt	137534	0644	edit dl rm
ossaudiodev.rst.txt	17845	0644	edit dl rm
othergui.rst.txt	2822	0644	edit dl rm
parser.rst.txt	15148	0644	edit dl rm
pathlib.rst.txt	30045	0644	edit dl rm
pdb.rst.txt	19454	0644	edit dl rm
persistence.rst.txt	591	0644	edit dl rm
pickle.rst.txt	37440	0644	edit dl rm
pickletools.rst.txt	3729	0644	edit dl rm
pipes.rst.txt	2557	0644	edit dl rm
pkgutil.rst.txt	8730	0644	edit dl rm
platform.rst.txt	9624	0644	edit dl rm
plistlib.rst.txt	7398	0644	edit dl rm
poplib.rst.txt	8197	0644	edit dl rm
posix.rst.txt	3694	0644	edit dl rm
pprint.rst.txt	14274	0644	edit dl rm
profile.rst.txt	27969	0644	edit dl rm
pty.rst.txt	3123	0644	edit dl rm
pwd.rst.txt	2739	0644	edit dl rm
pyclbr.rst.txt	3297	0644	edit dl rm
pydoc.rst.txt	4688	0644	edit dl rm
pyexpat.rst.txt	28620	0644	edit dl rm
python.rst.txt	475	0644	edit dl rm
py_compile.rst.txt	3851	0644	edit dl rm
queue.rst.txt	7268	0644	edit dl rm
quopri.rst.txt	2571	0644	edit dl rm
random.rst.txt	18503	0644	edit dl rm
re.rst.txt	64936	0644	edit dl rm
readline.rst.txt	11943	0644	edit dl rm
reprlib.rst.txt	5162	0644	edit dl rm
resource.rst.txt	12291	0644	edit dl rm
rlcompleter.rst.txt	2294	0644	edit dl rm
runpy.rst.txt	8285	0644	edit dl rm
sched.rst.txt	4842	0644	edit dl rm
secrets.rst.txt	5930	0644	edit dl rm
select.rst.txt	28175	0644	edit dl rm
selectors.rst.txt	8925	0644	edit dl rm
shelve.rst.txt	8390	0644	edit dl rm
shlex.rst.txt	16441	0644	edit dl rm
shutil.rst.txt	26014	0644	edit dl rm
signal.rst.txt	17218	0644	edit dl rm
site.rst.txt	9628	0644	edit dl rm
smtpd.rst.txt	10806	0644	edit dl rm
smtplib.rst.txt	23439	0644	edit dl rm
sndhdr.rst.txt	1994	0644	edit dl rm
socket.rst.txt	68202	0644	edit dl rm
socketserver.rst.txt	23712	0644	edit dl rm
spwd.rst.txt	2958	0644	edit dl rm
sqlite3.rst.txt	39215	0644	edit dl rm
ssl.rst.txt	96021	0644	edit dl rm
stat.rst.txt	9805	0644	edit dl rm
statistics.rst.txt	15301	0644	edit dl rm
stdtypes.rst.txt	179240	0644	edit dl rm
string.rst.txt	35374	0644	edit dl rm
stringprep.rst.txt	4279	0644	edit dl rm
struct.rst.txt	19581	0644	edit dl rm
subprocess.rst.txt	45793	0644	edit dl rm
sunau.rst.txt	7390	0644	edit dl rm
superseded.rst.txt	258	0644	edit dl rm
symbol.rst.txt	975	0644	edit dl rm
symtable.rst.txt	4964	0644	edit dl rm
sys.rst.txt	58273	0644	edit dl rm
sysconfig.rst.txt	8749	0644	edit dl rm
syslog.rst.txt	4302	0644	edit dl rm
tabnanny.rst.txt	2007	0644	edit dl rm
tarfile.rst.txt	31749	0644	edit dl rm
telnetlib.rst.txt	7899	0644	edit dl rm
tempfile.rst.txt	13857	0644	edit dl rm
termios.rst.txt	3751	0644	edit dl rm
test.rst.txt	25764	0644	edit dl rm
text.rst.txt	584	0644	edit dl rm
textwrap.rst.txt	10519	0644	edit dl rm
threading.rst.txt	39257	0644	edit dl rm
time.rst.txt	32967	0644	edit dl rm
timeit.rst.txt	13000	0644	edit dl rm
tk.rst.txt	1639	0644	edit dl rm
tkinter.rst.txt	33027	0644	edit dl rm
tkinter.scrolledtext.rst.txt	1255	0644	edit dl rm
tkinter.tix.rst.txt	22653	0644	edit dl rm
tkinter.ttk.rst.txt	58489	0644	edit dl rm
token.rst.txt	2607	0644	edit dl rm
tokenize.rst.txt	10002	0644	edit dl rm
trace.rst.txt	6914	0644	edit dl rm
traceback.rst.txt	17854	0644	edit dl rm
tracemalloc.rst.txt	22089	0644	edit dl rm
tty.rst.txt	1097	0644	edit dl rm
turtle.rst.txt	71221	0644	edit dl rm
types.rst.txt	9999	0644	edit dl rm
typing.rst.txt	34332	0644	edit dl rm
undoc.rst.txt	780	0644	edit dl rm
unicodedata.rst.txt	5762	0644	edit dl rm
unittest.mock-examples.rst.txt	46206	0644	edit dl rm
unittest.mock.rst.txt	85991	0644	edit dl rm
unittest.rst.txt	93304	0644	edit dl rm
unix.rst.txt	446	0644	edit dl rm
urllib.error.rst.txt	2199	0644	edit dl rm
urllib.parse.rst.txt	27332	0644	edit dl rm
urllib.request.rst.txt	59360	0644	edit dl rm
urllib.robotparser.rst.txt	2969	0644	edit dl rm
urllib.rst.txt	466	0644	edit dl rm
uu.rst.txt	2387	0644	edit dl rm
uuid.rst.txt	8760	0644	edit dl rm
venv.rst.txt	20621	0644	edit dl rm
warnings.rst.txt	20152	0644	edit dl rm
wave.rst.txt	6870	0644	edit dl rm
weakref.rst.txt	21328	0644	edit dl rm
webbrowser.rst.txt	9783	0644	edit dl rm
windows.rst.txt	272	0644	edit dl rm
winreg.rst.txt	24073	0644	edit dl rm
winsound.rst.txt	5134	0644	edit dl rm
wsgiref.rst.txt	33047	0644	edit dl rm
xdrlib.rst.txt	8078	0644	edit dl rm
xml.dom.minidom.rst.txt	10198	0644	edit dl rm
xml.dom.pulldom.rst.txt	5186	0644	edit dl rm
xml.dom.rst.txt	39507	0644	edit dl rm
xml.etree.elementtree.rst.txt	43871	0644	edit dl rm
xml.rst.txt	6071	0644	edit dl rm
xml.sax.handler.rst.txt	15399	0644	edit dl rm
xml.sax.reader.rst.txt	12133	0644	edit dl rm
xml.sax.rst.txt	7159	0644	edit dl rm
xml.sax.utils.rst.txt	3901	0644	edit dl rm
xmlrpc.client.rst.txt	23071	0644	edit dl rm
xmlrpc.rst.txt	475	0644	edit dl rm
xmlrpc.server.rst.txt	14990	0644	edit dl rm
zipapp.rst.txt	17392	0644	edit dl rm
zipfile.rst.txt	24005	0644	edit dl rm
zipimport.rst.txt	5805	0644	edit dl rm
zlib.rst.txt	13912	0644	edit dl rm
_dummy_thread.rst.txt	762	0644	edit dl rm
_thread.rst.txt	6886	0644	edit dl rm
__future__.rst.txt	5245	0644	edit dl rm
__main__.rst.txt	904	0644	edit dl rm

Edit: /usr/share/doc/python3-docs/html/_sources/library/xml.etree.elementtree.rst.txt (43871B)

:mod:`xml.etree.ElementTree` --- The ElementTree XML API
========================================================

.. module:: xml.etree.ElementTree
   :synopsis: Implementation of the ElementTree API.

.. moduleauthor:: Fredrik Lundh <fredrik@pythonware.com>

**Source code:** :source:`Lib/xml/etree/ElementTree.py`

--------------

The :mod:`xml.etree.ElementTree` module implements a simple and efficient API
for parsing and creating XML data.

.. versionchanged:: 3.3
   This module will use a fast implementation whenever available.
   The :mod:`xml.etree.cElementTree` module is deprecated.

.. warning::

The :mod:`xml.etree.ElementTree` module is not secure against
   maliciously constructed data.  If you need to parse untrusted or
   unauthenticated data see :ref:`xml-vulnerabilities`.

Tutorial
--------

This is a short tutorial for using :mod:`xml.etree.ElementTree` (``ET`` in
short).  The goal is to demonstrate some of the building blocks and basic
concepts of the module.

XML tree and elements
^^^^^^^^^^^^^^^^^^^^^

XML is an inherently hierarchical data format, and the most natural way to
represent it is with a tree.  ``ET`` has two classes for this purpose -
:class:`ElementTree` represents the whole XML document as a tree, and
:class:`Element` represents a single node in this tree.  Interactions with
the whole document (reading and writing to/from files) are usually done
on the :class:`ElementTree` level.  Interactions with a single XML element
and its sub-elements are done on the :class:`Element` level.

.. _elementtree-parsing-xml:

Parsing XML
^^^^^^^^^^^

We'll be using the following XML document as the sample data for this section:

.. code-block:: xml

<?xml version="1.0"?>
 <data>
 <country name="Liechtenstein">
 <rank>1</rank>
 <year>2008</year>
 <gdppc>141100</gdppc>
 <neighbor name="Austria" direction="E"/>
 <neighbor name="Switzerland" direction="W"/>
 </country>
 <country name="Singapore">
 <rank>4</rank>
 <year>2011</year>
 <gdppc>59900</gdppc>
 <neighbor name="Malaysia" direction="N"/>
 </country>
 <country name="Panama">
 <rank>68</rank>
 <year>2011</year>
 <gdppc>13600</gdppc>
 <neighbor name="Costa Rica" direction="W"/>
 <neighbor name="Colombia" direction="E"/>
 </country>
 </data>

We can import this data by reading from a file::

import xml.etree.ElementTree as ET
   tree = ET.parse('country_data.xml')
   root = tree.getroot()

Or directly from a string::

root = ET.fromstring(country_data_as_string)

:func:`fromstring` parses XML from a string directly into an :class:`Element`,
which is the root element of the parsed tree.  Other parsing functions may
create an :class:`ElementTree`.  Check the documentation to be sure.

As an :class:`Element`, ``root`` has a tag and a dictionary of attributes::

>>> root.tag
   'data'
   >>> root.attrib
   {}

It also has children nodes over which we can iterate::

>>> for child in root:
   ...     print(child.tag, child.attrib)
   ...
   country {'name': 'Liechtenstein'}
   country {'name': 'Singapore'}
   country {'name': 'Panama'}

Children are nested, and we can access specific child nodes by index::

>>> root[0][1].text
   '2008'

.. note::

Not all elements of the XML input will end up as elements of the
   parsed tree. Currently, this module skips over any XML comments,
   processing instructions, and document type declarations in the
   input. Nevertheless, trees built using this module's API rather
   than parsing from XML text can have comments and processing
   instructions in them; they will be included when generating XML
   output. A document type declaration may be accessed by passing a
   custom :class:`TreeBuilder` instance to the :class:`XMLParser`
   constructor.

.. _elementtree-pull-parsing:

Pull API for non-blocking parsing
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Most parsing functions provided by this module require the whole document
to be read at once before returning any result.  It is possible to use an
:class:`XMLParser` and feed data into it incrementally, but it is a push API that
calls methods on a callback target, which is too low-level and inconvenient for
most needs.  Sometimes what the user really wants is to be able to parse XML
incrementally, without blocking operations, while enjoying the convenience of
fully constructed :class:`Element` objects.

The most powerful tool for doing this is :class:`XMLPullParser`.  It does not
require a blocking read to obtain the XML data, and is instead fed with data
incrementally with :meth:`XMLPullParser.feed` calls.  To get the parsed XML
elements, call :meth:`XMLPullParser.read_events`.  Here is an example::

>>> parser = ET.XMLPullParser(['start', 'end'])
 >>> parser.feed('<mytag>sometext')
 >>> list(parser.read_events())
 [('start', <Element 'mytag' at 0x7fa66db2be58>)]
 >>> parser.feed(' more text</mytag>')
 >>> for event, elem in parser.read_events():
 ... print(event)
 ... print(elem.tag, 'text=', elem.text)
 ...
 end

The obvious use case is applications that operate in a non-blocking fashion
where the XML data is being received from a socket or read incrementally from
some storage device.  In such cases, blocking reads are unacceptable.

Because it's so flexible, :class:`XMLPullParser` can be inconvenient to use for
simpler use-cases.  If you don't mind your application blocking on reading XML
data but would still like to have incremental parsing capabilities, take a look
at :func:`iterparse`.  It can be useful when you're reading a large XML document
and don't want to hold it wholly in memory.

Finding interesting elements
^^^^^^^^^^^^^^^^^^^^^^^^^^^^

:class:`Element` has some useful methods that help iterate recursively over all
the sub-tree below it (its children, their children, and so on).  For example,
:meth:`Element.iter`::

>>> for neighbor in root.iter('neighbor'):
   ...     print(neighbor.attrib)
   ...
   {'name': 'Austria', 'direction': 'E'}
   {'name': 'Switzerland', 'direction': 'W'}
   {'name': 'Malaysia', 'direction': 'N'}
   {'name': 'Costa Rica', 'direction': 'W'}
   {'name': 'Colombia', 'direction': 'E'}

:meth:`Element.findall` finds only elements with a tag which are direct
children of the current element.  :meth:`Element.find` finds the *first* child
with a particular tag, and :attr:`Element.text` accesses the element's text
content.  :meth:`Element.get` accesses the element's attributes::

>>> for country in root.findall('country'):
   ...     rank = country.find('rank').text
   ...     name = country.get('name')
   ...     print(name, rank)
   ...
   Liechtenstein 1
   Singapore 4
   Panama 68

More sophisticated specification of which elements to look for is possible by
using :ref:`XPath <elementtree-xpath>`.

Modifying an XML File
^^^^^^^^^^^^^^^^^^^^^

:class:`ElementTree` provides a simple way to build XML documents and write them to files.
The :meth:`ElementTree.write` method serves this purpose.

Once created, an :class:`Element` object may be manipulated by directly changing
its fields (such as :attr:`Element.text`), adding and modifying attributes
(:meth:`Element.set` method), as well as adding new children (for example
with :meth:`Element.append`).

Let's say we want to add one to each country's rank, and add an ``updated``
attribute to the rank element::

>>> for rank in root.iter('rank'):
   ...     new_rank = int(rank.text) + 1
   ...     rank.text = str(new_rank)
   ...     rank.set('updated', 'yes')
   ...
   >>> tree.write('output.xml')

Our XML now looks like this:

.. code-block:: xml

<?xml version="1.0"?>
 <data>
 <country name="Liechtenstein">
 <rank updated="yes">2</rank>
 <year>2008</year>
 <gdppc>141100</gdppc>
 <neighbor name="Austria" direction="E"/>
 <neighbor name="Switzerland" direction="W"/>
 </country>
 <country name="Singapore">
 <rank updated="yes">5</rank>
 <year>2011</year>
 <gdppc>59900</gdppc>
 <neighbor name="Malaysia" direction="N"/>
 </country>
 <country name="Panama">
 <rank updated="yes">69</rank>
 <year>2011</year>
 <gdppc>13600</gdppc>
 <neighbor name="Costa Rica" direction="W"/>
 <neighbor name="Colombia" direction="E"/>
 </country>
 </data>

We can remove elements using :meth:`Element.remove`.  Let's say we want to
remove all countries with a rank higher than 50::

>>> for country in root.findall('country'):
   ...     rank = int(country.find('rank').text)
   ...     if rank > 50:
   ...         root.remove(country)
   ...
   >>> tree.write('output.xml')

Our XML now looks like this:

.. code-block:: xml

Building XML documents
^^^^^^^^^^^^^^^^^^^^^^

The :func:`SubElement` function also provides a convenient way to create new
sub-elements for a given element::

>>> a = ET.Element('a')
 >>> b = ET.SubElement(a, 'b')
 >>> c = ET.SubElement(a, 'c')
 >>> d = ET.SubElement(c, 'd')
 >>> ET.dump(a)
 <a><c><d /></c></a>

Parsing XML with Namespaces
^^^^^^^^^^^^^^^^^^^^^^^^^^^

If the XML input has `namespaces
<https://en.wikipedia.org/wiki/XML_namespace>`__, tags and attributes
with prefixes in the form ``prefix:sometag`` get expanded to
``{uri}sometag`` where the *prefix* is replaced by the full *URI*.
Also, if there is a `default namespace
<https://www.w3.org/TR/xml-names/#defaulting>`__,
that full URI gets prepended to all of the non-prefixed tags.

Here is an XML example that incorporates two namespaces, one with the
prefix "fictional" and the other serving as the default namespace:

.. code-block:: xml

<?xml version="1.0"?>
 <actors xmlns:fictional="http://characters.example.com"
 xmlns="http://people.example.com">
 <actor>
 <name>John Cleese</name>
 <fictional:character>Lancelot</fictional:character>
 <fictional:character>Archie Leach</fictional:character>
 </actor>
 <actor>
 <name>Eric Idle</name>
 <fictional:character>Sir Robin</fictional:character>
 <fictional:character>Gunther</fictional:character>
 <fictional:character>Commander Clement</fictional:character>
 </actor>
 </actors>

One way to search and explore this XML example is to manually add the
URI to every tag or attribute in the xpath of a
:meth:`~Element.find` or :meth:`~Element.findall`::

root = fromstring(xml_text)
    for actor in root.findall('{http://people.example.com}actor'):
        name = actor.find('{http://people.example.com}name')
        print(name.text)
        for char in actor.findall('{http://characters.example.com}character'):
            print(' |-->', char.text)

A better way to search the namespaced XML example is to create a
dictionary with your own prefixes and use those in the search functions::

ns = {'real_person': 'http://people.example.com',
          'role': 'http://characters.example.com'}

for actor in root.findall('real_person:actor', ns):
        name = actor.find('real_person:name', ns)
        print(name.text)
        for char in actor.findall('role:character', ns):
            print(' |-->', char.text)

These two approaches both output::

Additional resources
^^^^^^^^^^^^^^^^^^^^

See http://effbot.org/zone/element-index.htm for tutorials and links to other
docs.

.. _elementtree-xpath:

XPath support
-------------

This module provides limited support for
`XPath expressions <https://www.w3.org/TR/xpath>`_ for locating elements in a
tree. The goal is to support a small subset of the abbreviated syntax; a full
XPath engine is outside the scope of the module.

Example
^^^^^^^

Here's an example that demonstrates some of the XPath capabilities of the
module. We'll be using the ``countrydata`` XML document from the
:ref:`Parsing XML <elementtree-parsing-xml>` section::

import xml.etree.ElementTree as ET

root = ET.fromstring(countrydata)

# Top-level elements
   root.findall(".")

# All 'neighbor' grand-children of 'country' children of the top-level
   # elements
   root.findall("./country/neighbor")

# Nodes with name='Singapore' that have a 'year' child
   root.findall(".//year/..[@name='Singapore']")

# 'year' nodes that are children of nodes with name='Singapore'
   root.findall(".//*[@name='Singapore']/year")

# All 'neighbor' nodes that are the second child of their parent
   root.findall(".//neighbor[2]")

Supported XPath syntax
^^^^^^^^^^^^^^^^^^^^^^

.. tabularcolumns:: |l|L|

+-----------------------+------------------------------------------------------+
| Syntax                | Meaning                                              |
+=======================+======================================================+
| ``tag``               | Selects all child elements with the given tag.       |
|                       | For example, ``spam`` selects all child elements     |
|                       | named ``spam``, and ``spam/egg`` selects all         |
|                       | grandchildren named ``egg`` in all children named    |
|                       | ``spam``.                                            |
+-----------------------+------------------------------------------------------+
| ``*``                 | Selects all child elements.  For example, ``*/egg``  |
|                       | selects all grandchildren named ``egg``.             |
+-----------------------+------------------------------------------------------+
| ``.``                 | Selects the current node.  This is mostly useful     |
|                       | at the beginning of the path, to indicate that it's  |
|                       | a relative path.                                     |
+-----------------------+------------------------------------------------------+
| ``//``                | Selects all subelements, on all levels beneath the   |
|                       | current  element.  For example, ``.//egg`` selects   |
|                       | all ``egg`` elements in the entire tree.             |
+-----------------------+------------------------------------------------------+
| ``..``                | Selects the parent element.  Returns ``None`` if the |
|                       | path attempts to reach the ancestors of the start    |
|                       | element (the element ``find`` was called on).        |
+-----------------------+------------------------------------------------------+
| ``[@attrib]``         | Selects all elements that have the given attribute.  |
+-----------------------+------------------------------------------------------+
| ``[@attrib='value']`` | Selects all elements for which the given attribute   |
|                       | has the given value.  The value cannot contain       |
|                       | quotes.                                              |
+-----------------------+------------------------------------------------------+
| ``[tag]``             | Selects all elements that have a child named         |
|                       | ``tag``.  Only immediate children are supported.     |
+-----------------------+------------------------------------------------------+
| ``[tag='text']``      | Selects all elements that have a child named         |
|                       | ``tag`` whose complete text content, including       |
|                       | descendants, equals the given ``text``.              |
+-----------------------+------------------------------------------------------+
| ``[position]``        | Selects all elements that are located at the given   |
|                       | position.  The position can be either an integer     |
|                       | (1 is the first position), the expression ``last()`` |
|                       | (for the last position), or a position relative to   |
|                       | the last position (e.g. ``last()-1``).               |
+-----------------------+------------------------------------------------------+

Predicates (expressions within square brackets) must be preceded by a tag
name, an asterisk, or another predicate.  ``position`` predicates must be
preceded by a tag name.

Reference
---------

.. _elementtree-functions:

Functions
^^^^^^^^^

.. function:: Comment(text=None)

Comment element factory.  This factory function creates a special element
   that will be serialized as an XML comment by the standard serializer.  The
   comment string can be either a bytestring or a Unicode string.  *text* is a
   string containing the comment string.  Returns an element instance
   representing a comment.

Note that :class:`XMLParser` skips over comments in the input
   instead of creating comment objects for them. An :class:`ElementTree` will
   only contain comment nodes if they have been inserted into to
   the tree using one of the :class:`Element` methods.

.. function:: dump(elem)

Writes an element tree or element structure to sys.stdout.  This function
   should be used for debugging only.

The exact output format is implementation dependent.  In this version, it's
   written as an ordinary XML file.

*elem* is an element tree or an individual element.

.. function:: fromstring(text)

Parses an XML section from a string constant.  Same as :func:`XML`.  *text*
   is a string containing XML data.  Returns an :class:`Element` instance.

.. function:: fromstringlist(sequence, parser=None)

Parses an XML document from a sequence of string fragments.  *sequence* is a
   list or other sequence containing XML data fragments.  *parser* is an
   optional parser instance.  If not given, the standard :class:`XMLParser`
   parser is used.  Returns an :class:`Element` instance.

.. versionadded:: 3.2

.. function:: iselement(element)

Checks if an object appears to be a valid element object.  *element* is an
   element instance.  Returns a true value if this is an element object.

.. function:: iterparse(source, events=None, parser=None)

Parses an XML section into an element tree incrementally, and reports what's
   going on to the user.  *source* is a filename or :term:`file object`
   containing XML data.  *events* is a sequence of events to report back.  The
   supported events are the strings ``"start"``, ``"end"``, ``"start-ns"`` and
   ``"end-ns"`` (the "ns" events are used to get detailed namespace
   information).  If *events* is omitted, only ``"end"`` events are reported.
   *parser* is an optional parser instance.  If not given, the standard
   :class:`XMLParser` parser is used.  *parser* must be a subclass of
   :class:`XMLParser` and can only use the default :class:`TreeBuilder` as a
   target.  Returns an :term:`iterator` providing ``(event, elem)`` pairs.

Note that while :func:`iterparse` builds the tree incrementally, it issues
   blocking reads on *source* (or the file it names).  As such, it's unsuitable
   for applications where blocking reads can't be made.  For fully non-blocking
   parsing, see :class:`XMLPullParser`.

.. note::

:func:`iterparse` only guarantees that it has seen the ">" character of a
      starting tag when it emits a "start" event, so the attributes are defined,
      but the contents of the text and tail attributes are undefined at that
      point.  The same applies to the element children; they may or may not be
      present.

If you need a fully populated element, look for "end" events instead.

.. deprecated:: 3.4
      The *parser* argument.

.. function:: parse(source, parser=None)

Parses an XML section into an element tree.  *source* is a filename or file
   object containing XML data.  *parser* is an optional parser instance.  If
   not given, the standard :class:`XMLParser` parser is used.  Returns an
   :class:`ElementTree` instance.

.. function:: ProcessingInstruction(target, text=None)

PI element factory.  This factory function creates a special element that
   will be serialized as an XML processing instruction.  *target* is a string
   containing the PI target.  *text* is a string containing the PI contents, if
   given.  Returns an element instance, representing a processing instruction.

Note that :class:`XMLParser` skips over processing instructions
   in the input instead of creating comment objects for them. An
   :class:`ElementTree` will only contain processing instruction nodes if
   they have been inserted into to the tree using one of the
   :class:`Element` methods.

.. function:: register_namespace(prefix, uri)

Registers a namespace prefix.  The registry is global, and any existing
   mapping for either the given prefix or the namespace URI will be removed.
   *prefix* is a namespace prefix.  *uri* is a namespace uri.  Tags and
   attributes in this namespace will be serialized with the given prefix, if at
   all possible.

.. versionadded:: 3.2

.. function:: SubElement(parent, tag, attrib={}, **extra)

Subelement factory.  This function creates an element instance, and appends
   it to an existing element.

The element name, attribute names, and attribute values can be either
   bytestrings or Unicode strings.  *parent* is the parent element.  *tag* is
   the subelement name.  *attrib* is an optional dictionary, containing element
   attributes.  *extra* contains additional attributes, given as keyword
   arguments.  Returns an element instance.

.. function:: tostring(element, encoding="us-ascii", method="xml", *, \
                       short_empty_elements=True)

Generates a string representation of an XML element, including all
   subelements.  *element* is an :class:`Element` instance.  *encoding* [1]_ is
   the output encoding (default is US-ASCII).  Use ``encoding="unicode"`` to
   generate a Unicode string (otherwise, a bytestring is generated).  *method*
   is either ``"xml"``, ``"html"`` or ``"text"`` (default is ``"xml"``).
   *short_empty_elements* has the same meaning as in :meth:`ElementTree.write`.
   Returns an (optionally) encoded string containing the XML data.

.. versionadded:: 3.4
      The *short_empty_elements* parameter.

.. function:: tostringlist(element, encoding="us-ascii", method="xml", *, \
                           short_empty_elements=True)

Generates a string representation of an XML element, including all
   subelements.  *element* is an :class:`Element` instance.  *encoding* [1]_ is
   the output encoding (default is US-ASCII).  Use ``encoding="unicode"`` to
   generate a Unicode string (otherwise, a bytestring is generated).  *method*
   is either ``"xml"``, ``"html"`` or ``"text"`` (default is ``"xml"``).
   *short_empty_elements* has the same meaning as in :meth:`ElementTree.write`.
   Returns a list of (optionally) encoded strings containing the XML data.
   It does not guarantee any specific sequence, except that
   ``b"".join(tostringlist(element)) == tostring(element)``.

.. versionadded:: 3.2

.. versionadded:: 3.4
      The *short_empty_elements* parameter.

.. function:: XML(text, parser=None)

Parses an XML section from a string constant.  This function can be used to
   embed "XML literals" in Python code.  *text* is a string containing XML
   data.  *parser* is an optional parser instance.  If not given, the standard
   :class:`XMLParser` parser is used.  Returns an :class:`Element` instance.

.. function:: XMLID(text, parser=None)

Parses an XML section from a string constant, and also returns a dictionary
   which maps from element id:s to elements.  *text* is a string containing XML
   data.  *parser* is an optional parser instance.  If not given, the standard
   :class:`XMLParser` parser is used.  Returns a tuple containing an
   :class:`Element` instance and a dictionary.

.. _elementtree-element-objects:

Element Objects
^^^^^^^^^^^^^^^

.. class:: Element(tag, attrib={}, **extra)

Element class.  This class defines the Element interface, and provides a
   reference implementation of this interface.

The element name, attribute names, and attribute values can be either
   bytestrings or Unicode strings.  *tag* is the element name.  *attrib* is
   an optional dictionary, containing element attributes.  *extra* contains
   additional attributes, given as keyword arguments.

.. attribute:: tag

A string identifying what kind of data this element represents (the
      element type, in other words).

.. attribute:: text
                  tail

These attributes can be used to hold additional data associated with
      the element.  Their values are usually strings but may be any
      application-specific object.  If the element is created from
      an XML file, the *text* attribute holds either the text between
      the element's start tag and its first child or end tag, or ``None``, and
      the *tail* attribute holds either the text between the element's
      end tag and the next tag, or ``None``.  For the XML data

.. code-block:: xml

the *a* element has ``None`` for both *text* and *tail* attributes,
      the *b* element has *text* ``"1"`` and *tail* ``"4"``,
      the *c* element has *text* ``"2"`` and *tail* ``None``,
      and the *d* element has *text* ``None`` and *tail* ``"3"``.

To collect the inner text of an element, see :meth:`itertext`, for
      example ``"".join(element.itertext())``.

Applications may store arbitrary objects in these attributes.

.. attribute:: attrib

A dictionary containing the element's attributes.  Note that while the
      *attrib* value is always a real mutable Python dictionary, an ElementTree
      implementation may choose to use another internal representation, and
      create the dictionary only if someone asks for it.  To take advantage of
      such implementations, use the dictionary methods below whenever possible.

The following dictionary-like methods work on the element attributes.

.. method:: clear()

Resets an element.  This function removes all subelements, clears all
      attributes, and sets the text and tail attributes to ``None``.

.. method:: get(key, default=None)

Gets the element attribute named *key*.

Returns the attribute value, or *default* if the attribute was not found.

.. method:: items()

Returns the element attributes as a sequence of (name, value) pairs.  The
      attributes are returned in an arbitrary order.

.. method:: keys()

Returns the elements attribute names as a list.  The names are returned
      in an arbitrary order.

.. method:: set(key, value)

Set the attribute *key* on the element to *value*.

The following methods work on the element's children (subelements).

.. method:: append(subelement)

Adds the element *subelement* to the end of this element's internal list
      of subelements.  Raises :exc:`TypeError` if *subelement* is not an
      :class:`Element`.

.. method:: extend(subelements)

Appends *subelements* from a sequence object with zero or more elements.
      Raises :exc:`TypeError` if a subelement is not an :class:`Element`.

.. versionadded:: 3.2

.. method:: find(match, namespaces=None)

Finds the first subelement matching *match*. *match* may be a tag name
 or a :ref:`path <elementtree-xpath>`. Returns an element instance
 or ``None``. *namespaces* is an optional mapping from namespace prefix
 to full name.

.. method:: findall(match, namespaces=None)

Finds all matching subelements, by tag name or
 :ref:`path <elementtree-xpath>`. Returns a list containing all matching
 elements in document order. *namespaces* is an optional mapping from
 namespace prefix to full name.

.. method:: findtext(match, default=None, namespaces=None)

Finds text for the first subelement matching *match*. *match* may be
 a tag name or a :ref:`path <elementtree-xpath>`. Returns the text content
 of the first matching element, or *default* if no element was found.
 Note that if the matching element has no text content an empty string
 is returned. *namespaces* is an optional mapping from namespace prefix
 to full name.

.. method:: getchildren()

.. deprecated:: 3.2
         Use ``list(elem)`` or iteration.

.. method:: getiterator(tag=None)

.. deprecated:: 3.2
         Use method :meth:`Element.iter` instead.

.. method:: insert(index, subelement)

Inserts *subelement* at the given position in this element.  Raises
      :exc:`TypeError` if *subelement* is not an :class:`Element`.

.. method:: iter(tag=None)

Creates a tree :term:`iterator` with the current element as the root.
      The iterator iterates over this element and all elements below it, in
      document (depth first) order.  If *tag* is not ``None`` or ``'*'``, only
      elements whose tag equals *tag* are returned from the iterator.  If the
      tree structure is modified during iteration, the result is undefined.

.. versionadded:: 3.2

.. method:: iterfind(match, namespaces=None)

Finds all matching subelements, by tag name or
 :ref:`path <elementtree-xpath>`. Returns an iterable yielding all
 matching elements in document order. *namespaces* is an optional mapping
 from namespace prefix to full name.

.. versionadded:: 3.2

.. method:: itertext()

Creates a text iterator.  The iterator loops over this element and all
      subelements, in document order, and returns all inner text.

.. versionadded:: 3.2

.. method:: makeelement(tag, attrib)

Creates a new element object of the same type as this element.  Do not
      call this method, use the :func:`SubElement` factory function instead.

.. method:: remove(subelement)

Removes *subelement* from the element.  Unlike the find\* methods this
      method compares elements based on the instance identity, not on tag value
      or contents.

:class:`Element` objects also support the following sequence type methods
   for working with subelements: :meth:`~object.__delitem__`,
   :meth:`~object.__getitem__`, :meth:`~object.__setitem__`,
   :meth:`~object.__len__`.

Caution: Elements with no subelements will test as ``False``.  This behavior
   will change in future versions.  Use specific ``len(elem)`` or ``elem is
   None`` test instead. ::

element = root.find('foo')

if not element:  # careful!
         print("element not found, or element has no subelements")

if element is None:
         print("element not found")

.. _elementtree-elementtree-objects:

ElementTree Objects
^^^^^^^^^^^^^^^^^^^

.. class:: ElementTree(element=None, file=None)

ElementTree wrapper class.  This class represents an entire element
   hierarchy, and adds some extra support for serialization to and from
   standard XML.

*element* is the root element.  The tree is initialized with the contents
   of the XML *file* if given.

.. method:: _setroot(element)

Replaces the root element for this tree.  This discards the current
      contents of the tree, and replaces it with the given element.  Use with
      care.  *element* is an element instance.

.. method:: find(match, namespaces=None)

Same as :meth:`Element.find`, starting at the root of the tree.

.. method:: findall(match, namespaces=None)

Same as :meth:`Element.findall`, starting at the root of the tree.

.. method:: findtext(match, default=None, namespaces=None)

Same as :meth:`Element.findtext`, starting at the root of the tree.

.. method:: getiterator(tag=None)

.. deprecated:: 3.2
         Use method :meth:`ElementTree.iter` instead.

.. method:: getroot()

Returns the root element for this tree.

.. method:: iter(tag=None)

Creates and returns a tree iterator for the root element.  The iterator
      loops over all elements in this tree, in section order.  *tag* is the tag
      to look for (default is to return all elements).

.. method:: iterfind(match, namespaces=None)

Same as :meth:`Element.iterfind`, starting at the root of the tree.

.. versionadded:: 3.2

.. method:: parse(source, parser=None)

Loads an external XML section into this element tree.  *source* is a file
      name or :term:`file object`.  *parser* is an optional parser instance.
      If not given, the standard :class:`XMLParser` parser is used.  Returns the
      section root element.

.. method:: write(file, encoding="us-ascii", xml_declaration=None, \
                     default_namespace=None, method="xml", *, \
                     short_empty_elements=True)

Writes the element tree to a file, as XML.  *file* is a file name, or a
      :term:`file object` opened for writing.  *encoding* [1]_ is the output
      encoding (default is US-ASCII).
      *xml_declaration* controls if an XML declaration should be added to the
      file.  Use ``False`` for never, ``True`` for always, ``None``
      for only if not US-ASCII or UTF-8 or Unicode (default is ``None``).
      *default_namespace* sets the default XML namespace (for "xmlns").
      *method* is either ``"xml"``, ``"html"`` or ``"text"`` (default is
      ``"xml"``).
      The keyword-only *short_empty_elements* parameter controls the formatting
      of elements that contain no content.  If ``True`` (the default), they are
      emitted as a single self-closed tag, otherwise they are emitted as a pair
      of start/end tags.

The output is either a string (:class:`str`) or binary (:class:`bytes`).
      This is controlled by the *encoding* argument.  If *encoding* is
      ``"unicode"``, the output is a string; otherwise, it's binary.  Note that
      this may conflict with the type of *file* if it's an open
      :term:`file object`; make sure you do not try to write a string to a
      binary stream and vice versa.

.. versionadded:: 3.4
         The *short_empty_elements* parameter.

This is the XML file that is going to be manipulated::

<html>
 <head>
 <title>Example page</title>
 </head>
 <body>
 Moved to <a href="http://example.org/">example.org</a>
 or <a href="http://example.com/">example.com</a>.
 </body>
 </html>

Example of changing the attribute "target" of every link in first paragraph::

>>> from xml.etree.ElementTree import ElementTree
 >>> tree = ElementTree()
 >>> tree.parse("index.xhtml")
 <Element 'html' at 0xb77e6fac>
 >>> p = tree.find("body/p") # Finds first occurrence of tag p in body
 >>> p
 <Element 'p' at 0xb77ec26c>
 >>> links = list(p.iter("a")) # Returns list of all links
 >>> links
 [<Element 'a' at 0xb77ec2ac>, <Element 'a' at 0xb77ec1cc>]
 >>> for i in links: # Iterates through all found links
 ... i.attrib["target"] = "blank"
 >>> tree.write("output.xhtml")

.. _elementtree-qname-objects:

QName Objects
^^^^^^^^^^^^^

.. class:: QName(text_or_uri, tag=None)

QName wrapper.  This can be used to wrap a QName attribute value, in order
   to get proper namespace handling on output.  *text_or_uri* is a string
   containing the QName value, in the form {uri}local, or, if the tag argument
   is given, the URI part of a QName.  If *tag* is given, the first argument is
   interpreted as a URI, and this argument is interpreted as a local name.
   :class:`QName` instances are opaque.

.. _elementtree-treebuilder-objects:

TreeBuilder Objects
^^^^^^^^^^^^^^^^^^^

.. class:: TreeBuilder(element_factory=None)

Generic element structure builder.  This builder converts a sequence of
   start, data, and end method calls to a well-formed element structure.  You
   can use this class to build an element structure using a custom XML parser,
   or a parser for some other XML-like format.  *element_factory*, when given,
   must be a callable accepting two positional arguments: a tag and
   a dict of attributes.  It is expected to return a new element instance.

.. method:: close()

Flushes the builder buffers, and returns the toplevel document
      element.  Returns an :class:`Element` instance.

.. method:: data(data)

Adds text to the current element.  *data* is a string.  This should be
      either a bytestring, or a Unicode string.

.. method:: end(tag)

Closes the current element.  *tag* is the element name.  Returns the
      closed element.

.. method:: start(tag, attrs)

Opens a new element.  *tag* is the element name.  *attrs* is a dictionary
      containing element attributes.  Returns the opened element.

In addition, a custom :class:`TreeBuilder` object can provide the
   following method:

.. method:: doctype(name, pubid, system)

Handles a doctype declaration.  *name* is the doctype name.  *pubid* is
      the public identifier.  *system* is the system identifier.  This method
      does not exist on the default :class:`TreeBuilder` class.

.. versionadded:: 3.2

.. _elementtree-xmlparser-objects:

XMLParser Objects
^^^^^^^^^^^^^^^^^

.. class:: XMLParser(html=0, target=None, encoding=None)

This class is the low-level building block of the module.  It uses
   :mod:`xml.parsers.expat` for efficient, event-based parsing of XML.  It can
   be fed XML data incrementally with the :meth:`feed` method, and parsing
   events are translated to a push API - by invoking callbacks on the *target*
   object.  If *target* is omitted, the standard :class:`TreeBuilder` is used.
   The *html* argument was historically used for backwards compatibility and is
   now deprecated.  If *encoding* [1]_ is given, the value overrides the
   encoding specified in the XML file.

.. deprecated:: 3.4
      The *html* argument.  The remaining arguments should be passed via
      keyword to prepare for the removal of the *html* argument.

.. method:: close()

Finishes feeding data to the parser.  Returns the result of calling the
      ``close()`` method of the *target* passed during construction; by default,
      this is the toplevel document element.

.. method:: doctype(name, pubid, system)

.. deprecated:: 3.2
         Define the :meth:`TreeBuilder.doctype` method on a custom TreeBuilder
         target.

.. method:: feed(data)

Feeds data to the parser.  *data* is encoded data.

:meth:`XMLParser.feed` calls *target*\'s ``start(tag, attrs_dict)`` method
   for each opening tag, its ``end(tag)`` method for each closing tag, and data
   is processed by method ``data(data)``.  :meth:`XMLParser.close` calls
   *target*\'s method ``close()``. :class:`XMLParser` can be used not only for
   building a tree structure. This is an example of counting the maximum depth
   of an XML file::

>>> from xml.etree.ElementTree import XMLParser
 >>> class MaxDepth: # The target object of the parser
 ... maxDepth = 0
 ... depth = 0
 ... def start(self, tag, attrib): # Called for each opening tag.
 ... self.depth += 1
 ... if self.depth > self.maxDepth:
 ... self.maxDepth = self.depth
 ... def end(self, tag): # Called for each closing tag.
 ... self.depth -= 1
 ... def data(self, data):
 ... pass # We do not need to do anything with data.
 ... def close(self): # Called when all data has been parsed.
 ... return self.maxDepth
 ...
 >>> target = MaxDepth()
 >>> parser = XMLParser(target=target)
 >>> exampleXml = """
 ... <a>
 ... 
 ... 
 ... 
 ... <c>
 ... <d>
 ... </d>
 ... </c>
 ... 
 ... </a>"""
 >>> parser.feed(exampleXml)
 >>> parser.close()
 4

.. _elementtree-xmlpullparser-objects:

XMLPullParser Objects
^^^^^^^^^^^^^^^^^^^^^

.. class:: XMLPullParser(events=None)

A pull parser suitable for non-blocking applications.  Its input-side API is
   similar to that of :class:`XMLParser`, but instead of pushing calls to a
   callback target, :class:`XMLPullParser` collects an internal list of parsing
   events and lets the user read from it. *events* is a sequence of events to
   report back.  The supported events are the strings ``"start"``, ``"end"``,
   ``"start-ns"`` and ``"end-ns"`` (the "ns" events are used to get detailed
   namespace information).  If *events* is omitted, only ``"end"`` events are
   reported.

.. method:: feed(data)

Feed the given bytes data to the parser.

.. method:: close()

Signal the parser that the data stream is terminated. Unlike
      :meth:`XMLParser.close`, this method always returns :const:`None`.
      Any events not yet retrieved when the parser is closed can still be
      read with :meth:`read_events`.

.. method:: read_events()

Return an iterator over the events which have been encountered in the
      data fed to the
      parser.  The iterator yields ``(event, elem)`` pairs, where *event* is a
      string representing the type of event (e.g. ``"end"``) and *elem* is the
      encountered :class:`Element` object.

Events provided in a previous call to :meth:`read_events` will not be
      yielded again.  Events are consumed from the internal queue only when
      they are retrieved from the iterator, so multiple readers iterating in
      parallel over iterators obtained from :meth:`read_events` will have
      unpredictable results.

.. note::

:class:`XMLPullParser` only guarantees that it has seen the ">"
      character of a starting tag when it emits a "start" event, so the
      attributes are defined, but the contents of the text and tail attributes
      are undefined at that point.  The same applies to the element children;
      they may or may not be present.

If you need a fully populated element, look for "end" events instead.

.. versionadded:: 3.4

Exceptions
^^^^^^^^^^

.. class:: ParseError

XML parse error, raised by the various parsing methods in this module when
   parsing fails.  The string representation of an instance of this exception
   will contain a user-friendly error message.  In addition, it will have
   the following attributes available:

.. attribute:: code

A numeric error code from the expat parser. See the documentation of
      :mod:`xml.parsers.expat` for the list of error codes and their meanings.

.. attribute:: position

A tuple of *line*, *column* numbers, specifying where the error occurred.

.. rubric:: Footnotes

.. [1] The encoding string included in XML output should conform to the
   appropriate standards.  For example, "UTF-8" is valid, but "UTF8" is
   not.  See https://www.w3.org/TR/2006/REC-xml11-20060816/#NT-EncodingDecl
   and https://www.iana.org/assignments/character-sets/character-sets.xhtml.

cmd: