判断是否为单元

    elif word.endswith('单元') :
        if i > 0 and words[i-1].isdigit():
            tag_list.append('B-cellno')
            cellno = words[i-1] + word
            roadno = words[i-1]
        else:
            for char in word:
                if char == word[0]:
                    tag_list.append('B-cellno')
                elif char == word[-1]:
                    tag_list.append('E-cellno')
                else:
                    tag_list.append('I-cellno')
            cellno = word
            roadno = wor