Testing For A Number (python)

[shanenin]

lets say I have a list called lis

lis = [(1, 2), (3, 4), (5, 6), (7, 8)]

lets say I want to test for a numner in the first position of each tuple. to give you an idea of what I want to do, I will show you code that does not work, but might make my point

if 3 in lis[0-3][0]:

the code would read if 3 is in the first position of the first four tuples:

[jcl]

Hmm. My inclination would be to use map

if 3 in map(lambda(t): t[0], lis):

, but kind of thing is discouraged in Python these days, or a list comprehension

if [i for i in lis if i[0] == 3]:

but neither is very efficient.

Edited August 14, 2005 by jcl

[shanenin]

thanks. I like the list comprehension. That is sure to come in handy again.

I did it this way

if 3 in [ i[0] for i in lis ]:

Edited August 14, 2005 by shanenin