Python重新查找组匹配的开始和结束索引

Question

Python 的重新匹配对象在匹配对象上有 .start() 和 .end() 方法。我想找到小组比赛的开始和结束索引。我怎样才能做到这一点？例子：

>>> import re
>>> REGEX = re.compile(r'h(?P<num>[0-9]{3})p')
>>> test = "hello h889p something"
>>> match = REGEX.search(test)
>>> match.group('num')
'889'
>>> match.start()
6
>>> match.end()
11
>>> match.group('num').start()                  # just trying this. Didn't work
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'str' object has no attribute 'start'
>>> REGEX.groupindex
mappingproxy({'num': 1})                        # this is the index of the group in the regex, not the index of the group match, so not what I'm looking for.

上面的预期输出是 (7, 10)

Answer 1

您可以提供Match.start( 和Match.end) 组名称来获取组的开始（结束）位置：

>>> import re
>>> REGEX = re.compile(r'h(?P<num>[0-9]{3})p')
>>> test = "hello h889p something"
>>> match = REGEX.search(test)
>>> match.start('num')
7
>>> match.end('num')
10

与其他答案中建议的使用方法相比，这种方法的优点str.index是，如果组字符串多次出现，您不会遇到问题。