David Raymond <david.raym...@tomtom.com> writes: >> This is true. I have written 0 as false in C so many times. But >> clearly for me times have changed... I now look at numbers as a thing >> in their own special class not to be confused as truth-values. (So much >> so that I fell for this.) But I confess I still think of numbers as all >> TRUE. (Even zero!) > > Also remember that in Python bool is a subclass of int: >>>> isinstance(False, int) > True >>>> 0 == False > True >>>> 1 == True > True >>>> ["A", "B"][False] > 'A' >>>> ["A", "B"][True] > 'B' > > So if you're trying to do something slightly different based on the > type of the input you might fall into this trap > > if isinstance(foo, float): > do float stuff > elif isinstance(foo, int): > do int stuff > elif isinstance(foo, bool): > this line will never run because it would have triggered the int line
In my case I was only interested in ints, so I actually did try isinstance(k, int) and it seemed to work because I didn't try k = False I settled for the explicit check done by Chris Angelico. -- https://mail.python.org/mailman/listinfo/python-list
