Checking for empty element

[amoeba]

I'm trying to check if an array index exist, however it keeps failing for me.

if my_list[foo] == 1:

It breaks if there's no element at foo yet. Can I test for it somehow? I tried

if my_list[foo] == None:


but that doesn't work either. In C I used to check if the array index is NULL, not sure about python.

Thanks for your help!