Examples of common python Regular Expressions and python examples

Examples of common python Regular Expressions and python examples

The following lists the matching usage 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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