python中正则表达式的用法【非原创】
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字符串匹配
1.测试正则表达式是否匹配字符串的全部或部分 regex=ur"" #正则表达式
if re.search(regex, subject):
do_something()
else:
do_anotherthing() |
| 2.测试正则表达式是否匹配整个字符串
regex=ur"\Z" #正则表达式末尾以\Z结束
if re.match(regex, subject):
do_something()
else:
do_anotherthing()
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| 3.创建一个匹配对象，然后通过该对象获得匹配细节 (Create an object with details about how the regex matches (part of) a string)
regex=ur"" #正则表达式
match = re.search(regex, subject)
if match:
# match start: match.start()
# match end (exclusive): atch.end()
# matched text: match.group()
do_something()
else:
do_anotherthing()
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| 4.获取正则表达式所匹配的子串(Get the part of a string matched by the regex) regex=ur"" #正则表达式
match = re.search(regex, subject)
if match:
result = match.group()
else:
result = "" |
| 5. 获取捕获组所匹配的子串(Get the part of a string matched by a capturing group) regex=ur"" #正则表达式
match = re.search(regex, subject)
if match:
result = match.group(1)
else:
result = "" |
| 6. 获取有名组所匹配的子串(Get the part of a string matched by a named group) regex=ur"" #正则表达式
match = re.search(regex, subject)
if match:
result = match.group"groupname")
else:
result = "" |
| 7. 将字符串中所有匹配的子串放入数组中(Get an array of all regex matches in a string) result = re.findall(regex, subject) |
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8.遍历所有匹配的子串(Iterate over all matches in a string) for match in re.finditer(r"<(.*?)\s*.*?/\1>", subject)
# match start: match.start()
# match end (exclusive): atch.end()
# matched text: match.group() |
| 9.通过正则表达式字符串创建一个正则表达式对象 (Create an object to use the same regex for many operations) reobj = re.compile(regex) |
| 10.用法１的正则表达式对象版本（use regex object for if/else branch whether (part of) a string can be matched） reobj = re.compile(regex)
if reobj.search(subject):
do_something()
else:
do_anotherthing()
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| 11.用法２的正则表达式对象版本（use regex object for if/else branch whether a string can be matched entirely） reobj = re.compile(r"\Z") ＃正则表达式末尾以\Z 结束
if reobj.match(subject):
do_something()
else:
do_anotherthing() |
| 12.创建一个正则表达式对象，然后通过该对象获得匹配细节（Create an object with details about how the regex object matches (part of) a string） |
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reobj = re.compile(regex)
match = reobj.search(subject)
if match:
# match start: match.start()
# match end (exclusive): atch.end()
# matched text: match.group()
do_something()
else:
do_anotherthing() 13.用正则表达式对象获取匹配子串（Use regex object to get the part of a string matched by the regex） reobj = re.compile(regex)
match = reobj.search(subject)
if match:
result = match.group()
else:
result = "" |
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14.用正则表达式对象获取捕获组所匹配的子串（Use regex object to get the part of a string matched by a capturing group） reobj = re.compile(regex)
match = reobj.search(subject)
if match:
result = match.group(1)
else:
result = ""
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| 15.用正则表达式对象获取有名组所匹配的子串（Use regex object to get the part of a string matched by a named group） reobj = re.compile(regex)
match = reobj.search(subject)
if match:
result = match.group("groupname")
else:
result = ""
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| 16.用正则表达式对象获取所有匹配子串并放入数组（Use regex object to get an array of all regex matches in a string） reobj = re.compile(regex) result = reobj.findall(subject)
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| 17.通过正则表达式对象遍历所有匹配子串 （Use regex object to iterate over all matches in a string） reobj = re.compile(regex)
for match in reobj.finditer(subject):
# match start: match.start()
# match end (exclusive): match.end()
# matched text: match.group()
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字符串替换 1.替换所有匹配的子串
result = re.sub(regex, newstring, subject)
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2.替换所有匹配的子串（使用正则表达式对象） reobj = re.compile(regex) result = reobj.sub(newstring, subject)
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字符串拆分
result = re.split(regex, subject)
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| 2.字符串拆分（使用正则表示式对象）
reobj = re.compile(regex) result = reobj.split(subject)
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