Valid Word Abbreviation

class Solution:
    def validWordAbbreviation(self, word: str, abbr: str) -> bool:

        first = 0
        second = 0

        while (first < len(word) and second < len(abbr)):
            if word[first] == abbr[second]:
                first += 1
                second += 1
            elif (abbr[second] == '0'):
                return False
            elif abbr[second].isnumeric():
                count = 0
                while (second<len(abbr) and abbr[second].isnumeric()):
                    count = count*10 + int(abbr[second])
                    second += 1
                first = first + count
            else:
                return False # what if characters don't match; what if the

        return first == len(word) and second == len(abbr)