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| -rw-r--r-- | Doc/glossary.rst | 5 | ||||
| -rw-r--r-- | Doc/library/collections.abc.rst | 7 |
2 files changed, 10 insertions, 2 deletions
diff --git a/Doc/glossary.rst b/Doc/glossary.rst index dba9186..b947520 100644 --- a/Doc/glossary.rst +++ b/Doc/glossary.rst @@ -535,7 +535,10 @@ Glossary iterables include all sequence types (such as :class:`list`, :class:`str`, and :class:`tuple`) and some non-sequence types like :class:`dict`, :term:`file objects <file object>`, and objects of any classes you define - with an :meth:`__iter__` or :meth:`__getitem__` method. Iterables can be + with an :meth:`__iter__` method or with a :meth:`__getitem__` method + that implements :term:`Sequence` semantics. + + Iterables can be used in a :keyword:`for` loop and in many other places where a sequence is needed (:func:`zip`, :func:`map`, ...). When an iterable object is passed as an argument to the built-in function :func:`iter`, it returns an diff --git a/Doc/library/collections.abc.rst b/Doc/library/collections.abc.rst index 58b03b9..6015453 100644 --- a/Doc/library/collections.abc.rst +++ b/Doc/library/collections.abc.rst @@ -107,7 +107,12 @@ ABC Inherits from Abstract Methods Mixin .. class:: Iterable ABC for classes that provide the :meth:`__iter__` method. - See also the definition of :term:`iterable`. + + Checking ``isinstance(obj, Iterable)`` detects classes that are registered + as :class:`Iterable` or that have an :meth:`__iter__` method, but it does + not detect classes that iterate with the :meth:`__getitem__` method. + The only reliable way to determine whether an object is :term:`iterable` + is to call ``iter(obj)``. .. class:: Collection |