How to extract first items from a list of tuples [duplicate]

Question

I have a rather large list of tuples which contains:

[('and', 44023), ('cx', 37711), ('is', 36777), ...]

I just want to extract the first string, so the output for the above list would be:

and
cx
is

How do I code this (with extensibilty built in to some degree)?

Answer 1

[tup[0] for tup in mylist]

This uses a list comprehension. You could also use parentheses instead of the outer brackets to make it a generator comprehension, so evaluation would be lazy.

Answer 2

Just to provide an alternative way to the solution by Matthew.

tuples = [('and', 44023), ('cx', 37711), ('is', 36777) .... ]
strings, numbers = zip(*tuples)

In case you at some point decide you want both parts of the tuple in separate sequences (avoids two list comprehensions).

Answer 3

If you want to get the exact output

and
cx
is

Then use a list comprehension in combination with the strings join method to join the newline chararcter like so

yourList = [('and', 44023), ('cx', 37711), ('is', 36777)]
print '\n'.join([tup[0] for tup in yourList])