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authorR David Murray <rdmurray@bitdance.com>2014-01-05 04:52:50 (GMT)
committerR David Murray <rdmurray@bitdance.com>2014-01-05 04:52:50 (GMT)
commit410d320703313b6a303094b8355ae7cc1f0196f6 (patch)
treeafeaab503d68b01b002889d08115706085b26e96 /Doc
parentaed5b22ead9127103cea2de8722d36b90a320142 (diff)
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whatsnew: XMLPullParser, plus some doc updates.
I was confused by the text saying that read_events "iterated", since it actually returns an iterator (that's what a generator does) that the caller must then iterate. So I tidied up the language. I'm not sure what the sentence "Events provided in a previous call to read_events() will not be yielded again." is trying to convey, so I didn't try to fix that. Also fixed a couple more news items.
Diffstat (limited to 'Doc')
-rw-r--r--Doc/library/xml.etree.elementtree.rst23
-rw-r--r--Doc/whatsnew/3.4.rst7
2 files changed, 18 insertions, 12 deletions
diff --git a/Doc/library/xml.etree.elementtree.rst b/Doc/library/xml.etree.elementtree.rst
index 0731cd8..fb6da15 100644
--- a/Doc/library/xml.etree.elementtree.rst
+++ b/Doc/library/xml.etree.elementtree.rst
@@ -105,12 +105,15 @@ Children are nested, and we can access specific child nodes by index::
>>> root[0][1].text
'2008'
+
+.. _elementtree-pull-parsing:
+
Pull API for non-blocking parsing
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-Most parsing functions provided by this module require to read the whole
-document at once before returning any result. It is possible to use a
-:class:`XMLParser` and feed data into it incrementally, but it's a push API that
+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
@@ -119,7 +122,7 @@ 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's an example::
+elements, call :meth:`XMLPullParser.read_events`. Here is an example::
>>> parser = ET.XMLPullParser(['start', 'end'])
>>> parser.feed('<mytag>sometext')
@@ -1038,15 +1041,17 @@ XMLPullParser Objects
.. method:: read_events()
- Iterate over the events which have been encountered in the data fed to the
- parser. This method yields ``(event, elem)`` pairs, where *event* is a
+ 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. As events are consumed from the internal queue only as
- they are retrieved from the iterator, multiple readers calling
- :meth:`read_events` in parallel will have unpredictable results.
+ 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::
diff --git a/Doc/whatsnew/3.4.rst b/Doc/whatsnew/3.4.rst
index ab48020..f954f12 100644
--- a/Doc/whatsnew/3.4.rst
+++ b/Doc/whatsnew/3.4.rst
@@ -1088,9 +1088,10 @@ Richard Oudkerk in :issue:`15528`)
xml.etree
---------
-Add an event-driven parser for non-blocking applications,
-:class:`~xml.etree.ElementTree.XMLPullParser`.
-(Contributed by Antoine Pitrou in :issue:`17741`.)
+A new parser, :class:`~xml.etree.ElementTree.XMLPullParser`, allows a
+non-blocking applications to parse XML documents. An example can be
+seen at :ref:`elementtree-pull-parsing`. (Contributed by Antoine
+Pitrou in :issue:`17741`.)
The :mod:`xml.etree.ElementTree` :func:`~xml.etree.ElementTree.tostring` and
:func:`~xml.etree.ElementTree.tostringlist` functions, and the