python 重新: r'\b\$\d+\b' won't match 'aug 12, 2010 abc $123'

Question

所以我只是制作一个脚本来从事务日志类型文件中收集 $ 值

for line in sys.stdin:
    match = re.match( r'\b \$ (\d+) \b', line)
    if match is not None:
            for value in match.groups():
                    print value

现在我只是想打印这些值它会匹配包含 $12323 的行，但当该行中有其他内容时则不会根据我的阅读，它应该可以工作，但看起来我可能会遗漏一些东西

Answer 1

re.match :

If zero or more characters at the beginning of string match this regular expression, return a corresponding MatchObject instance. Return None if the string does not match the pattern; note that this is different from a zero-length match.

您正在寻找的是 re.search或 re.findall :

#!/usr/bin/env python

import re
s = 'aug 12, 2010 abc $123'

print re.findall(r'\$(\d+)', s)
# => ['123']

print re.search(r'\$(\d+)', s).group()
# => $123

print re.search(r'\$(\d+)', s).group(1)
# => 123