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Is object mutable? Determine programmatically.

Fredrik Lundh effbot at telia.com
Wed Sep 6 12:24:45 EDT 2000 
Tom wrote:
> I have a Python Object, and I want to determine if it is mutable.

You cannot.

> I could change a reference to it and see if the reference's id changes, but
> I don't know how to change an object of unknown type (ie. come up with a new
> value of the same type).  And I guess that the rules for changes in identity
> are implementation specific anyway.

Mutable objects provide one or more methods that allow you
to modify the object in place, immutable objects don't. Python
itself doesn't really care; it only copies references.

(you can use the "copy" module to copy values, but it doesn't
work on all types).

</F>

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