Semantics of ==
Axel Boldt
axelboldt at yahoo.com
Tue Mar 16 18:38:39 EST 2004
Still trying to understand "=="... It appears as if two equal objects
can become unequal if you perform the same operations on them:
>>> l=[1]
>>> s=l
>>> l.append(s)
>>> w=[1]
>>> r=[1,w]
>>> w.append(r)
>>> s
[1, [...]]
>>> w
[1, [1, [...]]]
>>> s==w
True
Note that they're equal, yet are printed differently.
>>> s[0]=2
>>> w[0]=2
>>> s==w
False
All of a sudden they have become unequal.
Axel
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