637. 检查缩写字

class Solution:
    """
    @param word: a non-empty string
    @param abbr: an abbreviation
    @return: true if string matches with the given abbr or false
    """
    def validWordAbbreviation(self, word, abbr):
        # write your code here
        #两根指针，一个指针走word，一个指针走abbr，最后判断是否相等即可
        left, right = 0, 0 
        len1, len2 = len(word), len(abbr)
        
        while left < len1 and right < len2:
            #当两者相等的话，相继加1
            if word[left] == abbr[right]:
                left += 1 
                right += 1 
            #如果abbr[right]为数字，不为0，为0直接False
            elif abbr[right].isdigit() == True  and abbr[right] != ‘0‘:
                start = right
                while right < len2 and abbr[right].isdigit() == True:
                    right += 1 
                
                #最后跳出循环，此时为完整的数字,abbr[start: right]
                left += int(abbr[start: right])
            
            #当两者word[left] != abbr[right] or abbr[right] == ‘0‘的话，返回False
            else:
                return False 
        
        #最后只需要判断两者长度是否相等
        return left == len1 and right == len2