Python - how many times does a word appear in a string

Question

Let's say I got the string a = "bob" and b = "bobob"

when I perform a in b, how can I count that bob appears twice in b?

Answer 1

You can use a generator expression that iterates through a rolling window of b over the difference in lengths between a and b and tests if the slice of b in that window is equal to a:

sum(b[i: i + len(a)] == a for i in range(len(b) - len(a) + 1))

This returns: 2