How to convert a list of string to a list of int

Question

I have this list in a list

a = [[\'1\',\'2\',\'3\',\'4\'],[\'1\',\'2\',\'3\',\'4\'],[\'1\',\'2\',\'3\',\'4\']]

but i need it to be ints , im

Answer 1

In [51]: a = [['1','2','3','4'],['1','2','3','4'],['1','2','3','4']]

In [52]: [map(int, l) for l in a]
Out[52]: [[1, 2, 3, 4], [1, 2, 3, 4], [1, 2, 3, 4]]