We might use range and len to skip items as we go:
S = 'abcdefghijk' print( list(range(0, len(S), 2)) ) for i in range(0, len(S), 2): print(S[i], end=' ')
Here, we visit every second item in the string S by stepping over the generated range list.
To visit every third item, change the third range argument to be 3, and so on.