Creating a Python list from a list of tuples

Question

If I have, for example, a list of tuples such as

a = [(1,2)] * 4

how would I create a list of the first element of each tuple? That is,

Answer 1

Assuming you have a list of tuples:

lta = [(1,2), (2,3), (44,45), (37,38)]

access the first element of each tuple would involve subscripting with [0], and visiting each tuple to extract each first element would involve a a list comprehension, which can be assigned to a variable as shown below:

resultant_list = [element[0] for element in lta]
>>> resultant_list
[1, 2, 44, 37]