list item's position

[Bob Smith]

Hi,

I have a Python list. I can't figure out how to find an element's 
numeric value (0,1,2,3...) in the list. Here's an example of what I'm doing:

for bar in bars:
    if 'str_1' in bar and 'str_2' in bar:
       print bar

This finds the right bar, but not its list position. The reason I need 
to find its value is so I can remove every element in the list before it 
so that the bar I found somewhere in the list becomes element 0... does 
that make sense?

Thanks,

Bob