re.MatchObject() Python

Match object对象有一个布尔值。可以通过if检查Mathch object是否匹配成功。Match object是re方法match()和seatch()返回的对象，没有匹配成功，返回None，否则True。group()，groups()方法返回Match object中的字符串：

<pre name="code" class="python">#pattern中的()用来分组 group(0)整个匹配到的match,group(1)为第一个，以此类推
>>> m = re.match(r"(\w+) (\w+)", "Isaac Newton, physicist")
>>> m.group(0)       # The entire match
'Isaac Newton'
>>> m.group(1)       # The first parenthesized subgroup.
'Isaac'
>>> m.group(2)       # The second parenthesized subgroup.
'Newton'
>>> m.group(1, 2)    # Multiple arguments give us a tuple.
('Isaac', 'Newton')

#groups()将分组匹配到的字符串作为元祖返回，没有匹配到的分组默认None
>>> m = re.match(r"(\d+)\.(\d+)", "24.1632")
>>> m.groups()
('24', '1632')

>>> m = re.match(r"(\d+)\.?(\d+)?", "24")
>>> m.groups()      # Second group defaults to None.
('24', None)
>>> m.groups('0')   # Now, the second group defaults to '0'.
('24', '0')