<轉自https://blog.csdn.net/suiyunonghen/article/details/3763261 作者：不得閑
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結束 if re.match(regex, subject): do_something() else: do_anotherthing()
3.創建一個匹配對象，然后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"" #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 = ""
- 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 = ""
- 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 = ""
- 將字符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 結束
if reobj.match(subject):
do_something()
else:
do_anotherthing()
12.創建一個正則表達式對象，然后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)