searching a list of tuples in python

Question

So I have a list of tuple like:

[(1,"juca"),(22,"james"),(53,"xuxa"),(44,"delicia")]

I want this list for a tuple whose number value is equal to something.

So that if I do search(53) it will return 2

Is is an easy way to do that?

Answer 1

Hmm... well, the simple way that comes to mind is to convert it to a dict

d = dict(thelist)

and access d[53].

EDIT: Oops, misread your question the first time. It sounds like you actually want to get the index where a given number is stored. In that case, try

dict((t[0], i) for i, t in enumerate(thelist))

instead of a plain old dict conversion. Then d[53] would be 2.

Answer 2

[i for i, v in enumerate(L) if v[0] == 53]

Answer 3

You can use a list comprehension:

>>> a = [(1,"juca"),(22,"james"),(53,"xuxa"),(44,"delicia")]
>>> [x[0] for x in a]
[1, 22, 53, 44]
>>> [x[0] for x in a].index(53)
2

Answer 4

Your tuples are basically key-value pairs--a python dict--so:

l = [(1,"juca"),(22,"james"),(53,"xuxa"),(44,"delicia")]
val = dict(l)[53]

Edit -- aha, you say you want the index value of (53, "xuxa"). If this is really what you want, you'll have to iterate through the original list, or perhaps make a more complicated dictionary:

d = dict((n,i) for (i,n) in enumerate(e[0] for e in l))
idx = d[53]