最长公共前缀(python) leetcode答案

直接上代码：

 def longestCommonPrefix(strs):
     """
     :type strs: List[str]
     :rtype: str
     """
     str_list = strs
     if len(str_list) > 1:
         s_last = str_list.pop()
         common_str = ''
         common = ''
         for num, str_ in enumerate(str_list):
             if num is 0:
                 if len(s_last) >= len(str_):
                     len_str = len(str_)
                 else:
                     len_str = len(s_last)
                 for i,j in enumerate(range(len_str)):
                     if s_last[i] == str_[i]:
                         common_str += s_last[i]
                     else:
                         break
                 if not common_str:
                     return ''
             else:
                 if len(common_str) >= len(str_):
                     len_str = len(str_)
                 else:
                     len_str = len(common_str)
                 for i,j in enumerate(range(len_str)):
                     if common_str[i] == str_[i]:
                         common = common_str[:i+1]
                     else:
                         common = common_str[:i]
                         if len(str_list) is 1:
                             return common_str
                         else:
                             return common
         if len(str_list) is 1:
             return common_str
         else:
             return common
     elif len(str_list) is 1:
         return str_list[0]
     else:
         return ''