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<title>6.5 Iterator Protocol
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<H1><A NAME=
"SECTION008500000000000000000"></A><A NAME=
"iterator"></A>
<span class=
"versionnote">New in version
2.2.
</span>
There are only a couple of functions specifically for working with
<dl><dt><table cellpadding=
"0" cellspacing=
"0"><tr valign=
"baseline"><td><nobr>int
<b><tt id='l2h-
346' xml:id='l2h-
346'
class=
"cfunction">PyIter_Check
</tt></b>(
</nobr></td><td>PyObject *
<var>o
</var>)
</td></tr></table></dt>
Return true if the object
<var>o
</var> supports the iterator protocol.
<dl><dt><table cellpadding=
"0" cellspacing=
"0"><tr valign=
"baseline"><td><nobr>PyObject*
<b><tt id='l2h-
347' xml:id='l2h-
347'
class=
"cfunction">PyIter_Next
</tt></b>(
</nobr></td><td>PyObject *
<var>o
</var>)
</td></tr></table></dt>
<div class=
"refcount-info">
<span class=
"label">Return value:
</span>
<span class=
"value">New reference.
</span>
Return the next value from the iteration
<var>o
</var>. If the object is
an iterator, this retrieves the next value from the iteration, and
returns
<tt class=
"constant">NULL
</tt> with no exception set if there are no remaining
items. If the object is not an iterator,
<tt class=
"exception">TypeError
</tt> is
raised, or if there is an error in retrieving the item, returns
<tt class=
"constant">NULL
</tt> and passes along the exception.
To write a loop which iterates over an iterator, the C code should
look something like this:
<div class=
"verbatim"><pre>
PyObject *iterator = PyObject_GetIter(obj);
while (item = PyIter_Next(iterator)) {
/* do something with item */
/* release reference when done */
/* continue doing useful work */
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<span class=
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2.4.2, documentation updated on
28 September
2005.
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