常見的python正則用法執行個體講解

下面列出PythonRegex的幾種匹配用法：
此外,關於正則的一切http://deerchao.net/tutorials/regex/regex.htm

1.測試Regex是否匹配字串的全部或部分

regex=ur"" #Regexif re.search(regex, subject): do_something()else: do_anotherthing()

2.測試Regex是否匹配整個字串

regex=ur"\Z" #Regex末尾以\Z結束if re.match(regex, subject):     do_something()else:     do_anotherthing()

3.建立一個匹配對象，然後通過該對象獲得匹配細節(Create an object with details about how the regex matches (part of) a string)

regex=ur"" #Regexmatch = re.search(regex, subject)if match:     # match start: match.start()     # match end (exclusive): atch.end()     # matched text: match.group()     do_something()else:     do_anotherthing()

4.擷取Regex所匹配的子串(Get the part of a string matched by the regex)

regex=ur"" #Regexmatch = re.search(regex, subject)if match:     result = match.group()else:     result = ""

5. 擷取擷取的群組所匹配的子串(Get the part of a string matched by a capturing group)

regex=ur"" #Regexmatch = re.search(regex, subject)if match:     result = match.group(1)else:     result = ""

6. 擷取有名組所匹配的子串(Get the part of a string matched by a named group)

regex=ur"" #Regexmatch = re.search(regex, subject) if match: result = match.group"groupname") else: result = ""

7. 將字串中所有匹配的子串放入數組中(Get an array of all regex matches in a string)

result = re.findall(regex, subject)

8.遍曆所有匹配的子串(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.通過Regex字串建立一個Regex對象(Create an object to use the same regex for many operations)

reobj = re.compile(regex)

10.用法１的Regex對象版本（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()

11.用法２的Regex對象版本（use regex object for if/else branch whether a string can be matched entirely）

reobj = re.compile(r"\Z")　＃Regex末尾以\Z 結束if reobj.match(subject):     do_something()else:     do_anotherthing()

12.建立一個Regex對象，然後通過該對象獲得匹配細節（Create an object with details about how the regex object matches (part of) a string）

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Regex對象擷取匹配子串（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 = ""

14.用Regex對象擷取擷取的群組所匹配的子串（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 = ""

15.用Regex對象擷取有名組所匹配的子串（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 = ""

16.用Regex對象擷取所有匹配子串並放入數組（Use regex object to get an array of all regex matches in a string）

reobj = re.compile(regex)
result = reobj.findall(subject)

17.通過Regex對象遍曆所有匹配子串（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()

18.字串替換
1).替換所有匹配的子串

#用newstring替換subject中所有與Regexregex匹配的子串
result = re.sub(regex, newstring, subject)

2).替換所有匹配的子串（使用Regex對象）

reobj = re.compile(regex)
result = reobj.sub(newstring, subject)

19.字串拆分
1).字串拆分

result = re.split(regex, subject)

2).字串拆分（使用正則表示式對象）
reobj = re.compile(regex)
result = reobj.split(subject)

以上就是本文的全部內容，希望對大家的學習有所協助，也希望大家多多支援指令碼之家。

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