Question

我试图找到字符串中一组字符的所有组合，但是找到的字符集必须具有特定的长度。我曾经想过使用set function []和出现次数函数{：}，我似乎无法让它们一起工作。

该示例应该返回＆＃39;这个＆＃39;和＆＃39;点击＆＃39;

谢谢。

def test_patterns(text, patterns=[]):
    """Given source text and a list of patterns, look for
    matches for each pattern within the text and print
    them to stdout.
    """
    # Look for each pattern in the text and print the results
    for pattern, desc in patterns:
        print "Pattern %r (%s)\n" % (pattern, desc)
        print ' %r' % text
        for match in re.finditer(pattern, text):
            s = match.start()
            e = match.end()
            #substr = match.group()
            substr = text[s:e]
            n_backslashes = text[:s].count('\\')
            prefix = '.' * (s + n_backslashes)
            print ' %s%r' % (prefix, substr)
        print
    return
if __name__ == '__main__':
    test_patterns('Does this text contain hits or matches?', [('[this]{4:4}+', "Description"),])
raw_input()

Answer 1

quatifier {m}要求以下正则表达式m次

例如

>>> st="Does this text contain hits or matches"
>>> re.findall(r'[this]{4}', st)
['this', 'hits']

或者更具体

>>> re.findall(r'\b[this]{4}\b', st)
['this', 'hits']

与写作相同

>>> re.findall(r'\b[this]{4,4}\b', st)
['this', 'hits']

Python Regex：设置前缀长度的组合

1 个答案: