擅长:python、mysql、java
<p>正则表达式是强大的,但有时它们过于致命。字符串方法应该可以用更少的思想完成您需要的任务</p>
<pre><code>>>> my_string = '#hello\n#monica, how re "u?\n#hello#robert\necho\nfall and spring'
>>> hash_positions = [index for index, c in enumerate(my_string) if c == '#']
>>> hash_positions
[0, 7, 27, 33]
>>> first = hash_positions[0]
>>> last = hash_positions[-1]
>>> new_line_after_last_hash = my_string.index('\n',last)
>>> new_line_after_last_hash
40
>>> new_string = my_string[first:new_line_after_last_hash]
>>> new_string
'#hello\n#monica, how re "u?\n#hello#robert'
</code></pre>