Check If Word Is Valid After Substitutions LeetCode solution in Python

1
class Solution:
2
    def isValid(self, s: str) -> bool:
3

4
        ans = ""
5
        for i in s:
6
            ans += i
7
            while len(ans) >= 3:
8
                if ans[-3:] == "abc":
9
                    ans = ans[0:-3]
10
                else:
11
                    break
12

13
        if ans == "":
14
            return True
15
        else:
16
            return False