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)