Python RE - finditer 和 findall 的不同匹配
这是一些代码：
>>> p = re.compile(r'\S+ (\[CC\] )+\S+')
>>> s1 = 'always look [CC] on the bright side'
>>> s2 = 'always look [CC] [CC] on the bright side'
>>> s3 = 'always look [CC] on the [CC] bright side'
>>> m1 = p.search(s1)
>>> m1.group()
'look [CC] on'
>>> p.findall(s1)
['[CC] ']
>>> itr = p.finditer(s1)
>>> for i in itr:
... i.group()
...
'look [CC] on'
显然，这与查找 s3 中的所有匹配项更相关，其中 findall() 返回：['[CC] ', '[ CC] ']，因为看起来 findall() 只匹配 p 中的内部组，而 finditer() 匹配整个模式。
为什么会发生这种情况？
（我定义了我的模式 p ，以便允许捕获包含重复的 [CC] 序列的模式，例如 s2 中的“look [CC] [CC] on”）。
Here is some code:
>>> p = re.compile(r'\S+ (\[CC\] )+\S+')
>>> s1 = 'always look [CC] on the bright side'
>>> s2 = 'always look [CC] [CC] on the bright side'
>>> s3 = 'always look [CC] on the [CC] bright side'
>>> m1 = p.search(s1)
>>> m1.group()
'look [CC] on'
>>> p.findall(s1)
['[CC] ']
>>> itr = p.finditer(s1)
>>> for i in itr:
... i.group()
...
'look [CC] on'
Obviously, this is more relevant for finding all matches in s3 in which findall() returns: ['[CC] ', '[CC] '], as it seems that findall() only matches the inner group in p, whereas finditer() matches the whole pattern.
Why is that happening?
(I defined my pattern p as I did in order to allow capturing patterns that contain repeated sequences of [CC]s such as 'look [CC] [CC] on' in s2).
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i.group()返回整个匹配项，包括组之前和之后的非空白字符。要获得与findall示例相同的结果，请使用i.group(1)http://docs.python.org/library/re.html#re.MatchObject.group
i.group()returns the whole match, including the non-whitespace characters before and after your group. To get the same result as in yourfindallexample, usei.group(1)http://docs.python.org/library/re.html#re.MatchObject.group