Python正則表達式使用經(jīng)典實例
下面列出Python正則表達式的幾種匹配用法,具體內(nèi)容如下所示:
此外,關于正則的一切http://deerchao.net/tutorials/regex/regex.htm
1.測試正則表達式是否匹配字符串的全部或部分
regex=ur"" #正則表達式 if re.search(regex, subject): do_something() else: do_anotherthing()
2.測試正則表達式是否匹配整個字符串
regex=ur"\Z" #正則表達式末尾以\Z結(jié)束 if re.match(regex, subject): do_something() else: do_anotherthing()
3.創(chuàng)建一個匹配對象,然后通過該對象獲得匹配細節(jié)(Create an object with details about how the regex matches (part of) a string)
regex=ur"" #正則表達式 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()
4.獲取正則表達式所匹配的子串(Get the part of a string matched by the regex)
regex=ur"" #正則表達式 match = re.search(regex, subject) if match: result = match.group() else: result = ""
5. 獲取捕獲組所匹配的子串(Get the part of a string matched by a capturing group)
regex=ur"" #正則表達式 match = re.search(regex, subject) if match: result = match.group(1) else: result = ""
6. 獲取有名組所匹配的子串(Get the part of a string matched by a named group)
regex=ur"" #正則表達式 match = re.search(regex, subject) if match: result = match.group"groupname") else: result = ""
7. 將字符串中所有匹配的子串放入數(shù)組中(Get an array of all regex matches in a string)
result = re.findall(regex, subject)
8.遍歷所有匹配的子串(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.通過正則表達式字符串創(chuàng)建一個正則表達式對象(Create an object to use the same regex for many operations)
reobj = re.compile(regex)
10.用法1的正則表達式對象版本(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的正則表達式對象版本(use regex object for if/else branch whether a string can be matched entirely)
reobj = re.compile(r"\Z") #正則表達式末尾以\Z 結(jié)束 if reobj.match(subject): do_something() else: do_anotherthing()
12.創(chuàng)建一個正則表達式對象,然后通過該對象獲得匹配細節(jié)(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.用正則表達式對象獲取匹配子串(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.用正則表達式對象獲取捕獲組所匹配的子串(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.用正則表達式對象獲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.用正則表達式對象獲取所有匹配子串并放入數(shù)組(Use regex object to get an array of all regex matches in a string)
reobj = re.compile(regex) result = reobj.findall(subject)
17.通過正則表達式對象遍歷所有匹配子串(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()
字符串替換
1.替換所有匹配的子串
#用newstring替換subject中所有與正則表達式regex匹配的子串 result = re.sub(regex, newstring, subject)
2.替換所有匹配的子串(使用正則表達式對象)
reobj = re.compile(regex) result = reobj.sub(newstring, subject)
字符串拆分
1.字符串拆分
result = re.split(regex, subject)
2.字符串拆分(使用正則表示式對象)
reobj = re.compile(regex) result = reobj.split(subject)
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