list item's position
Mark McEahern
marklists at mceahern.com
Wed Jan 19 22:29:50 EST 2005
Bob Smith wrote:
> 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:
Use enumerate() (new in Python 2.3, IIRC). Otherwise:
for i in range(len(sequence)):
item = sequence[i]
...
>
> 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?
Sure. You want to slice the list starting at the index of the first
occurrence:
index = min([i for i, item in enumerate(sequence) if 'str_1' in item and
'str_2' in item])
print sequence[index:]
// m
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