Convert List to integer in Python

Question

In Python, I want to convert list into int.

so if i have input like this:

a=[1,2,3,4]

i want this output:

1234

so How it is possible?

Answer 1

You can use the join function in conjunction with a generator, like this:

a=[1,2,3,4]

int(''.join(str(i) for i in a))

Output:

1234

Answer 2

With recursion:

a=[1,2,3,4]
def f(l):
    if not l: return 0
    return l[-1] + f(l[:-1]) * 10
print(f(a))

This outputs:

1234

Answer 3

You can use generator comprehension in the following way: result = int(''.join((str(i) for i in a)))

This turns every item of the list to a string, joins the list together and then turns the whole thing back to an integer