min/max: "stable" invariant?

Giovanni Bajo rasky at develer.com
Wed Mar 12 00:09:03 CET 2008


assuming that a sequence contains multiple elements with minimum/maximum 
value, do min/max guarantee to return the *first* element in the sequence 
among those?


>>> class A:
...     def __init__(self, x): self.x = x
>>> L = [A(0), A(1), A(2), A(0)]
>>> min(L, key=lambda a:a.x) is L[0]
>>> min(L, key=lambda a:a.x) is L[3]

Is this guaranteed by the Python language formal specification?
Is this guaranteed to always by true in CPython? (I guess so)

I can't find any mention in the documentation.
Giovanni Bajo

More information about the Python-list mailing list