Sort a list of tuples by 2nd item (integer value)

python list tuples
Amyth picture Amyth · May 22, 2012 · Viewed 397.4k times · Source

I have a list of tuples that looks something like this:

[('abc', 121),('abc', 231),('abc', 148), ('abc',221)]

I want to sort this list in ascending order by the integer value inside the tuples. Is it possible?

Answer

cheeken picture cheeken · May 22, 2012

Try using the key keyword with sorted().

sorted([('abc', 121),('abc', 231),('abc', 148), ('abc',221)], key=lambda x: x[1])

key should be a function that identifies how to retrieve the comparable element from your data structure. In your case, it is the second element of the tuple, so we access [1].

For optimization, see jamylak's response using itemgetter(1), which is essentially a faster version of lambda x: x[1].

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