Valid Word Abbreviation Python Solution

lcpy gen -n 408   # by problem number
lcpy gen -s valid_word_abbreviation   # by problem name

Input: word = "internationalization", abbr = "i12iz4n"
Output: true
Explanation: The word "internationalization" can be abbreviated as "i12iz4n" ("i nternational iz atio n").

Input: word = "apple", abbr = "a2e"
Output: false
Explanation: The word "apple" cannot be abbreviated as "a2e".

class Solution:
    # Time: O(n)
    # Space: O(1)
    def valid_word_abbreviation(self, word: str, abbr: str) -> bool:
        i = j = 0
        m, n = len(word), len(abbr)
        while i < m and j < n:
            if abbr[j].isdigit():
                if abbr[j] == "0":
                    return False
                count = 0
                while j < n and abbr[j].isdigit():
                    count = count * 10 + int(abbr[j])
                    j += 1
                i += count
            else:
                if word[i] != abbr[j]:
                    return False
                i += 1
                j += 1
        return i == m and j == n