刷CF的时候,看到一个简单的题目,可以用来练练正则表达式
于是乎找到了re.sub的用法,说明如下
re.sub: (pattern, repl, string, count=0,
│ flags=0)
│ Return the string obtained by replacing the leftmost
│ non-overlapping occurrences of the pattern in string by the
│ replacement repl. repl can be either a string or a callable;
│ if a string, backslash escapes in it are processed. If it is
│ a callable, it's passed the match object and must return
│ a replacement string to be used.
这段说明的意识是:在string中找到pattern,并且用repl来替换之
而且有趣的是,这里的repl可以是一个函数,此时,pattern会被作为参数
传给该函数,该函数必须提供一个换回值作为pattern的替换
count参数是用来说明匹配pattern的个数,默认为0,也就是没有约束