Problem with assigning variables of type List
abhishek at ocf.berkeley.edu
Thu Aug 22 16:56:11 EDT 2002
Peter Hansen <peter at engcorp.com> wrote in message news:<3D642244.D2B97B77 at engcorp.com>...
> I think it's probably pretty simple. Remember that in Python, all
> names are just things that are bound to objects. When you set
> the second item (numbered 1) in the sequence "a" to be "a", you
> are just storing a reference to the "a" object inside the object
> itself. Pretty much like having an array of pointers in C, and
> storing the address of the array as one of the array elements...
> When you make the comparison, it takes the left value which is
> the reference to "a", and the right value, which it retrieves
> from the second position in the sequence, and compares them.
> Since the right value is just a reference to "a" again, they
> compare equal. Effectively like comparing the pointers mentioned
> above, where they would also be equal.
By this reasoning Python's just checking id(a)==id(a). But that won't
Even more peculiarly,
causes Python (2.1.3) to hang.
More information about the Python-list