Convert list of tuples to list?

Question

How do I convert

[(1,), (2,), (3,)]

to

[1, 2, 3]

Answer 1

Here is another alternative if you can have a variable number of elements in the tuples:

>>> a = [(1,), (2, 3), (4, 5, 6)]
>>> [x for t in a for x in t]
[1, 2, 3, 4, 5, 6]

This is basically just a shortened form of the following loops:

result = []
for t in a:
    for x in t:
        result.append(x)

Answer 2

@Levon's solution works perfectly for your case.

As a side note, if you have variable number of elements in the tuples, you can also use chain from itertools.

>>> a = [(1, ), (2, 3), (4, 5, 6)]
>>> from itertools import chain
>>> list(chain(a))
[(1,), (2, 3), (4, 5, 6)]
>>> list(chain(*a))
[1, 2, 3, 4, 5, 6]
>>> list(chain.from_iterable(a)) # More efficient version than unpacking
[1, 2, 3, 4, 5, 6]

Answer 3

In these situations I like to do:

a = [(1,), (2,), (3,)]
new_a = [element for tup in a for element in tup]

This works even if your tuples have more than one element. This is equivalent to doing this:

a = [(1,), (2,), (3,)]
new_a = []
for tup in a:
    for element in tup:
        new_a.append(element)

Answer 4

One Liner yo!

list(*zip(*[(1,), (2,), (3,)]))

Answer 5

Using simple list comprehension:

e = [(1,), (2,), (3,)]
[i[0] for i in e]

will give you:

[1, 2, 3]