算法题目 - 简单分词 - Python

问题描述：

简单分词
1、每行代表一条记录
2、记录内的字段用逗号分隔
3、若字段内存在逗号，则用双引号包围整个字段
4、若字段内存在双引号，则在双引号前加一个双引号作为转义符，同时用双引号包围整个字段

输出的内容用\t分开。

示例 1:
输入:

Jack,"写""段子""",58,1963-10-28
Rommy,"读书,编程",63,1983-7-17
Kate,购物,49.6,1979-12-56
Jerry,"羽毛球,爬山",55.6,1980-5-26
Jane,"下棋,""飞""",56.2,1976-8-23

输出:

Jack    写"段子"   58  1963-10-28
Rommy   读书,编程   63  1983-7-17
Kate    购物  49.6    1979-12-56
Jerry   羽毛球,爬山  55.6    1980-5-26
Jane    下棋,"飞"  56.2    1976-8-23

问题分析：

使用栈操作。

Python3实现：

# 2018-05-09 面试题


def segmentation(s):
    msum, out, stmp, n = 0, [], '', len(s)
    for i in range(n):
        if s[i] == ',' and msum == 0:  # 第一种情况结束
            out.append(stmp)
            stmp = ''
        elif s[i] == '"':
            if stmp == '':  # 第二种情况的开头
                stmp = '@'
                msum += 1
            else:
                if stmp[-1] == '#':  # 说明已经进入一个'"'符号了，现在让它变成真正的双引号
                    stmp = stmp[:-1] + '"'
                    msum -= 1
                else:  # 说明还没有出现过
                    stmp = stmp + '#'  # 记录半个
                    msum += 1
        elif s[i] == ',' and msum == 2 and stmp[-1] == '#':  # 第二种情况结束
            out.append(stmp[1:-1])
            stmp, msum = '', 0
        else:
            stmp = stmp + s[i]  # 进栈
    if stmp[0] == '@':  # 最后一个单词要特殊处理
        out.append(stmp[1:-1])
    else:
        out.append(stmp)
    return '\t'.join(out)


if __name__ == '__main__':
    slist = ['Jack,"写""段子""",58,1963-10-28',
             'Rommy,"读书,编程",63,1983-7-17',
             'Kate,购物,49.6,1979-12-56',
             'Jerry,"羽毛球,爬山",55.6,1980-5-26',
             'Jane,"下棋,""飞""",56.2,1976-8-23',
             'Ndldl,"""北京,""飞""",86.2,",""1976-,8-23,"""']
    for s in slist:
        print(segmentation(s))

欢迎指正哦。