Examples of common python regular expressions

This article describes common python regular expression usage examples in detail and lists several matching usage of Python regular expressions, if you are interested, you can refer to the following several matching usages of Python regular expressions:
In addition, everything about regular expressions http://deerchao.net/tutorials/regex/regex.htm

1. test whether the regular expression matches all or part of the string.

Regex = ur "" # Regular expression if re. search (regex, subject): do_something () else: do_anotherthing ()

2. test whether the regular expression matches the entire string.

Regex = ur "\ Z" # end with \ Z at the end of the regular expression if re. match (regex, subject): do_something () else: do_anotherthing ()

3. Create a matching object and obtain the matching details through the object (Create an object with details about how the regex matches (part of) a string)

Regex = ur "" # Regular expression 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. Get the substring matched by the regular expression (Get the part of a string matched by the regex)

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

5. Get the part of a string matched by a capturing group)

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

6. Get the part of a string matched by a named group)

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

7. put all matched substrings in the string into the array (Get an array of all regex matches in a string)

Result = re. findall (regex, subject)

8. traverse all matched substrings (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. Create a regular expression object (Create an object to use the same regex for each operations)

Reobj = re. compile (regex)

10. 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. Regular expression object version (use regex object for if/else branch whether a string can be matched entirely)

Reobj = re. compile (r "\ Z") # end with \ Z at the end of the regular expression if reobj. match (subject): do_something () else: do_anotherthing ()

12. Create a regular expression object and obtain matching details through the object (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. Use a regular expression object to obtain a matched substring (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. Use a regular expression object to obtain the matched substring of the capture group (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. Use a regular expression object to obtain the matched substring of a famous group (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. Use a regular expression object to obtain all matched substrings and put them in an array (Use regex object to get an array of all regex matches in a string)

Reobj = re. compile (regex)
Result = reobj. findall (subject)

17. traverse all matched substrings through the regular expression object (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. string replacement
1). replace all matched substrings

# Replace all substrings in the subject with the regular expression regex with newstring
Result = re. sub (regex, newstring, subject)

2). replace all matched substrings (using regular expression objects)

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

19. string splitting
1). string splitting

Result = re. split (regex, subject)

2). string splitting (using regular expression objects)
Reobj = re. compile (regex)
Result = reobj. split (subject)

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