where is this documented? - Printable Version +- Python Forum (https://python-forum.io) +-- Forum: General (https://python-forum.io/forum-1.html) +--- Forum: News and Discussions (https://python-forum.io/forum-31.html) +--- Thread: where is this documented? (/thread-8362.html) |
where is this documented? - Skaperen - Feb-17-2018 the following code: foo = {}.update(os.environ)has a behavior that i have been unable to find documentation that describes (assuming import os has been done). does anyone know if such documentation exists and where that documentation can be found? i have PDF documentation for python version 3.5.2 but a reference in an HTML document of 3.4 or later should be good enough.
RE: where is this documented? - Larz60+ - Feb-17-2018 https://docs.python.org/3/library/stdtypes.html?highlight=dict%20update#dict.update RE: where is this documented? - Gribouillis - Feb-17-2018 According to the documentation, the behavior is the same as foo = None .
RE: where is this documented? - Skaperen - Feb-18-2018 (Feb-17-2018, 01:32 PM)Gribouillis Wrote: According to the documentation, the behavior is the same as my documentation (PDF letter format for 3.5.2) didn't give that information. maybe i need to switch back to the HTML documentation (been using PDF for 3+ years). RE: where is this documented? - Gribouillis - Feb-18-2018 If you read carefully, typing pydoc3 dict.update in a terminal gives the same information.
RE: where is this documented? - Skaperen - Feb-19-2018 yes, it sure does. i was not aware of this way to get python documentation. RE: where is this documented? - snippsat - Feb-19-2018 If have a "cool" editor mouse over update RE: where is this documented? - DeaD_EyE - Feb-19-2018 foo = {}.update(os.environ)foo is None because the method update returns None .You can do this technique with data types, which returns a new copy of them selfs if mutated (str does this). It's the same pitfall like this: sorted_list = [1,4,5,6,7,3,2].sort()list.sort() makes an inline sort (mutating the object itself) and returns None .
RE: where is this documented? - Skaperen - Feb-20-2018 i guess i am just used to methods that returned something useful. i did know about .sort but didn't think of it as another case. i usually use sorted(iterable) .
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