:class:`UserString` wrapper around string objects for easier string subclassing

===================== ====================================================================

.. deprecated-removed:: 3.3 3.9

.. deprecated-removed:: 3.3 3.10

Moved :ref:`collections-abstract-base-classes` to the :mod:`collections.abc` module.

For backwards compatibility, they continue to be visible in this module through

Python 3.8.

since Python 3.2.

(Contributed by Victor Stinner in :issue:`38916`.)

* The abstract base classes in :mod:`collections.abc` no longer are

exposed in the regular :mod:`collections` module. This will help

create a clearer distinction between the concrete classes and the abstract

base classes.

* The undocumented ``sys.callstats()`` function has been removed. Since Python

3.7, it was deprecated and always returned :const:`None`. It required a special

build option ``CALL_PROFILE`` which was already removed in Python 3.7.

pass

def __getattr__(name):

# For backwards compatibility, continue to make the collections ABCs

# through Python 3.6 available through the collections module.

# Note, no new collections ABCs were added in Python 3.7

if name in _collections_abc.__all__:

obj = getattr(_collections_abc, name)

import warnings

warnings.warn("Using or importing the ABCs from 'collections' instead "

"of from 'collections.abc' is deprecated since Python 3.3, "

"and in 3.10 it will stop working",

DeprecationWarning, stacklevel=2)

globals()[name] = obj

return obj

raise AttributeError(f'module {__name__!r} has no attribute {name!r}')

################################################################################

### OrderedDict

################################################################################

Revert "Do not expose abstract collection classes in the collections module"

change (bpo-25988). Aliases to ABC like collections.Mapping are kept in

Python 3.9 to ease transition from Python 2.7, but will be removed in Python

3.10.