Python - How to add space on each 3 characters?

Question

I need to add a space on each 3 characters of a python string but don\'t have many clues on how to do it.

The string:

345674655

The ou

Answer 1

Join with '-' the concatenated of the first, second and third characters of each 3 characters:

' '.join(a+b+c for a,b,c in zip(x[::3], x[1::3], x[2::3]))

Be sure string length is dividable by 3