backports — Python Backports#

This module contains backports to support older Python versions.

Deprecated since version 9.0: The nullcontext context manager; use contextlib.nullcontext instead. The SimpleQueue queue; use queue.SimpleQueue instead.

backports.batched(iterable, n, *, strict=False)[source]#

Batch data from the iterable into tuples of length n.

Note

The last batch may be shorter than n if strict is True or raise a ValueError otherwise.

Example:

>>> i = batched(range(25), 10)
>>> print(next(i))
(0, 1, 2, 3, 4, 5, 6, 7, 8, 9)
>>> print(next(i))
(10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
>>> print(next(i))
(20, 21, 22, 23, 24)
>>> print(next(i))
Traceback (most recent call last):
 ...
StopIteration
>>> list(batched('ABCD', 2))
[('A', 'B'), ('C', 'D')]
>>> list(batched('ABCD', 3, strict=False))
[('A', 'B', 'C'), ('D',)]
>>> list(batched('ABCD', 3, strict=True))
Traceback (most recent call last):
 ...
ValueError: batched(): incomplete batch

See also

itertools.batched, backported from Python 3.12.

Added in version 8.2.

Changed in version 9.0: Added strict option, backported from Python 3.13

Parameters:

  • n (int) – How many items of the iterable to get in one chunk

  • strict (bool) – raise a ValueError if the final batch is shorter than n.

Raises:

  • ValueError – batched(): incomplete batch

  • TypeError – n cannot be interpreted as an integer

Return type:

Generator[tuple]

backports.pairwise(iterable)[source]#

Return successive overlapping pairs taken from the input iterable.

See also

itertools.pairwise, backported from Python 3.10.

Added in version 7.6.

backports.removeprefix(string, prefix)[source]#

Remove prefix from a string or return a copy otherwise.

>>> removeprefix('TestHook', 'Test')
'Hook'
>>> removeprefix('BaseTestCase', 'Test')
'BaseTestCase'

See also

str.removeprefix, backported from Python 3.9.

Added in version 5.4.

Parameters:

  • string (str)

  • prefix (str)

Return type:

str

backports.removesuffix(string, suffix)[source]#

Remove suffix from a string or return a copy otherwise.

>>> removesuffix('MiscTests', 'Tests')
'Misc'
>>> removesuffix('TmpDirMixin', 'Tests')
'TmpDirMixin'

See also

str.removesuffix, backported from Python 3.9.

Added in version 5.4.

Parameters:

  • string (str)

  • suffix (str)

Return type:

str