[ python-Bugs-1297986 ] hashable and mutable functions

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Bugs item #1297986, was opened at 2005-09-21 17:55
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Category: Python Library
Group: None
Status: Open
Resolution: None
Priority: 5
Submitted By: ChristianJ (cybb20)
Assigned to: Nobody/Anonymous (nobody)
Summary: hashable and mutable functions

Initial Comment:
It is not easy to check if an object is hashable, ie
hasattr(list(), '__hash__') -> True 


try: hash(list())
except TypeError: pass

seems to be a possible way to see if an object is
hashable, however it is not satisfiable that this
information needs to be retrieved by using exception
handling.

My proposal:
There should be a hashable(obj) function returning a
bool object and additionally it would be nice to have
something like ismutable(obj) function, possibly as
built-in functions.

Reason:
callable() is a built-in function and returns
information about an object whether it's callable or
not, that is a basic info about this object. 
If an object is hashable or mutable is a state of an
object that is also very important to know.


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You can respond by visiting: 
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