wat.txt

Python 2.7.10 (default, Oct 23 2015, 19:19:21)
[GCC 4.2.1 Compatible Apple LLVM 7.0.0 (clang-700.0.59.5)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import string
>>> string.letters
'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'
>>> help(string)

>>> string.letters
'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz'

On ipython, it is already reversed the first time, and calling help on string doesn't change it. Tested on python 2.7.6, ubuntu 14.04, locale en_US UTF-8, ipython 5.1.0

@kms70847 I assume it has something to do with the fact that help sometimes launches a pager (i.e. less), but I haven't really looked into it yet.

Furthermore:

[GCC 6.2.0 20160914] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import string
>>> id(string.letters)
140641450093232
>>> help(string)

>>> id(string.letters)
140641450093232

@dschep that's not so surprising, the new string.letters just happens to get the same ID, same as this question. If you assign the original string.letters to a variable the updated string.letters will have a different ID.