[已解决]关于正则表达的问题

W1ND123

问题1：是哪里打错了呢，既然报错了
import re
re.search(r'(([01]{0,1}\d{0,1}\d|2[0-4]\d|25[0-5]\.){3}([01]{0,1}\d{0,1}\d|2[0-4]\d|25[0-5])', 'other192.168.1.1other')
Traceback (most recent call last):
  File "<pyshell#4>", line 1, in <module>
    re.search(r'(([01]{0,1}\d{0,1}\d|2[0-4]\d|25[0-5]\.){3}([01]{0,1}\d{0,1}\d|2[0-4]\d|25[0-5])', 'other192.168.1.1other')
  File "E:\pyhthon\lib\re.py", line 201, in search
    return _compile(pattern, flags).search(string)
  File "E:\pyhthon\lib\re.py", line 304, in _compile
    p = sre_compile.compile(pattern, flags)
  File "E:\pyhthon\lib\sre_compile.py", line 764, in compile
    p = sre_parse.parse(p, flags)
  File "E:\pyhthon\lib\sre_parse.py", line 948, in parse
    p = _parse_sub(source, state, flags & SRE_FLAG_VERBOSE, 0)
  File "E:\pyhthon\lib\sre_parse.py", line 443, in _parse_sub
    itemsappend(_parse(source, state, verbose, nested + 1,
  File "E:\pyhthon\lib\sre_parse.py", line 836, in _parse
    raise source.error("missing ), unterminated subpattern",
re.error: missing ), unterminated subpattern at position 0

问题2：红色是一个小组，那绿色的哪个小括号是干嘛的
re.search(r'(([01]{0,1}\d{0,1}\d|2[0-4]\d|25[0-5]\.){3}([01]{0,1}\d{0,1}\d|2[0-4]\d|25[0-5])', 'other192.168.1.1other')

最佳答案

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suchocolate

2021-11-28 11:33:03

W1ND123 发表于 2021-11-28 10:03
re.search(r'([01]{0,1}\d{0,1}\d|2[0-4]\d|25[0-5]\.){3}([01]{0,1}\d{0,1}\d|2[0-4]\d|25[0-5])', 'oth ...

abc{3}  # 只能匹配3个重复的c，即abccc
(abc){3}  # abc成为一组，可以匹配3组abc，即abcabcabc
基本功先练好，事半功倍。https://www.runoob.com/python3/python3-reg-expressions.html

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君无泪

# 这样可以匹配 192.168.1.1
import re
patterm = '[1-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}'
string = 'other192.168.1.1other'

print(re.search(patterm, string))

wp231957

缺括号吧

xugh123

r"([0-9]?[0-9]?[0-9]+.){3}[0-9]?[0-9]?[0-9]+"

W1ND123

wp231957 发表于 2021-11-27 11:20
缺括号吧

没有呀，和小甲鱼的一模一样

txxcat

提示很清楚了，差一个右括号。
re.search(r'(([01]{0,1}\d{0,1}\d|2[0-4]\d|25[0-5])\.){3}([01]{0,1}\d{0,1}\d|2[0-4]\d|25[0-5])', 'other192.168.1.1other')

W1ND123

txxcat 发表于 2021-11-27 16:49
提示很清楚了，差一个右括号。
re.search(r'(([01]{0,1}\d{0,1}\d|2[0-4]\d|25[0-5])\.){3}([01]{0,1}\d{0 ...

re.search(r'([01]{0,1}\d{0,1}\d|2[0-4]\d|25[0-5]\.){3}([01]{0,1}\d{0,1}\d|2[0-4]\d|25[0-5])', 'other192.168.1.1other')

这样子不是也可以代表红色小组重复三次嘛?
为什么要多一组括号呢，谢谢回答！

suchocolate

W1ND123 发表于 2021-11-28 10:03
re.search(r'([01]{0,1}\d{0,1}\d|2[0-4]\d|25[0-5]\.){3}([01]{0,1}\d{0,1}\d|2[0-4]\d|25[0-5])', 'oth ...

abc{3}  # 只能匹配3个重复的c，即abccc
(abc){3}  # abc成为一组，可以匹配3组abc，即abcabcabc
基本功先练好，事半功倍。https://www.runoob.com/python3/python3-reg-expressions.html