python - Convert Single integer into a list

There's nothing that will automatically treat an int as if it's a list of one int. You need to check whether the value is a list or not:

(a if type(a) is list else [a]) + (b if type(b) is list else [b]) + (c if type(c) is list else [c])

If you have to do this often you might want to write a function:

def as_list(x):
    if type(x) is list:
        return x
    else:
        return [x]

Then you can write:

as_list(a) + as_list(b) + as_list(c)

You can use itertools:

from itertools import chain

a = 1
b = [2,3]
c = [4,5,6]
final_list = list(chain.from_iterable([[a], b, c]))

Output:

[1, 2, 3, 4, 5, 6]

However, if you do not know the contents of a, b, and c ahead of time, you can try this:

new_list = [[i] if not isinstance(i, list) else i for i in [a, b, c]]
final_list = list(chain.from_iterable(new_list))

Related