According to the docs `itertools.repeat(object[, times])` is equivalent to

```
def repeat(object, times=None):
    # repeat(10, 3) --> 10 10 10
    if times is None:
        while True:
            yield object
    else:
        for i in range(times):
            yield object
```

But it raises a TypeError when used this way:

```
Python 3.5.1 (default, Dec 10 2015, 10:34:07)
[GCC 4.2.1 Compatible Apple LLVM 7.0.0 (clang-700.1.76)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> from itertools import repeat
>>> repeat('x', times=None)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'NoneType' object cannot be interpreted as an integer
```

The `times` keyword can be omitted but not explicitly set to None.
I checked with Python Versions 2.7 and 3.5.1 on Mac OS X and Windows 10.

Huh.  I always thought the wording was "roughly equivalent to".  This is a consequence of C vs python, and is the reason the docstring uses the [] notation.

Should 'roughly equivalent to' be added as a note to the docs?

I'm okay with changing the docs to "roughly equivalent to".  That will help prevent the occasional misreading as "precisely equivalent in every respect".

Issue #25926
Changed all "equivalent to" occurrences to "roughly equivalent to"

Attached a diff
All occurrences of "equivalent to" are switched to "roughly equivalent to"

New changeset 613314c3f9ed by Raymond Hettinger in branch '3.5':
Issue 25926:  Clarify that the pure python equivalents are only approximate.
https://hg.python.org/cpython/rev/613314c3f9ed

New changeset e67e970de54a by Raymond Hettinger in branch 'default':
Issue 25926:  Clarify that the pure python equivalents are only approximate.
https://hg.python.org/cpython/rev/e67e970de54a

New changeset f66c30f66235 by Raymond Hettinger in branch '2.7':
Issue 25926:  Clarify that the pure python equivalents are only approximate.
https://hg.python.org/cpython/rev/f66c30f66235

Nofar, thanks for the patch.

New changeset 35fa2ec1f237 by Serhiy Storchaka in branch 'default':
Merge heads (issue #25926).
https://hg.python.org/cpython/rev/35fa2ec1f237