Python正則表達(dá)式使用經(jīng)典實(shí)例

本文給大家總結(jié)了17種python正則表達(dá)式使用經(jīng)典實(shí)例，非常不錯(cuò)具有參考借鑒價(jià)值，下面列出Python正則表達(dá)式的幾種匹配用法，具體內(nèi)容如下所示：

1.測(cè)試正則表達(dá)式是否匹配字符串的全部或部分
regex=ur"" #正則表達(dá)式
if re.search(regex, subject):
do_something()
else:
do_anotherthing()

2.測(cè)試正則表達(dá)式是否匹配整個(gè)字符串    
regex=ur"\Z" #正則表達(dá)式末尾以\Z結(jié)束
if re.match(regex, subject):
    do_something()
else:
    do_anotherthing()

3.創(chuàng)建一個(gè)匹配對(duì)象，然后通過該對(duì)象獲得匹配細(xì)節(jié)(Create an object with details about how the regex matches (part of) a string)    
regex=ur"" #正則表達(dá)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(dá)式所匹配的子串(Get the part of a string matched by the regex)    
regex=ur"" #正則表達(dá)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(dá)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(dá)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(dá)式字符串創(chuàng)建一個(gè)正則表達(dá)式對(duì)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(dá)式對(duì)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(dá)式對(duì)象版本（use regex object for if/else branch whether a string can be matched entirely）
    
reobj = re.compile(r"\Z")?。?a href='/map/zhengzebiaodashi/' style='color:#000;font-size:inherit;'>正則表達(dá)式末尾以\Z 結(jié)束
if reobj.match(subject):
    do_something()
else:
    do_anotherthing()

12.創(chuàng)建一個(gè)正則表達(dá)式對(duì)象，然后通過該對(duì)象獲得匹配細(xì)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(dá)式對(duì)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(dá)式對(duì)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(dá)式對(duì)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(dá)式對(duì)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(dá)式對(duì)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(dá)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(dá)式對(duì)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(duì)象）    
reobj = re.compile(regex)
result = reobj.split(subject)