Python_re regular module

The method comprising the matching result or attribute sre.Match

Methods (properties)	meaning
match.group(index)	Gets the string specified group
match.__getitem__(g)	That match [0] = match.group (0)
match.groups()	Get all of the group results
match.span(index)	Gets the string matches the string in the index section taken
match.start(groupindex)	To obtain the starting position of the specified group substring
match.stop(groupindex)	Gets the end position of the specified group substring
match.re	Return re object model comprising
match.string	Return the original string
match.pos	pos parameter returns the object passed to the regular expression search (), match () method and the like

re.compile(p, flag=0)

String (str) -> Regular objects (_sre.SRE_Pattern)
such a program needs to be used multiple times with a regular string, you can consider in order to improve the efficiency of the compiler
```
p = re.compile("baidu")                 # 编译正则对象p
p.search("www.baidu.com")               # 效率高
re.search("du", "www.baidu.com")        # 效率低
```
re.match(p, string, flag=0)

Detecting whether the beginning of the match
successful return re.Match object is returned unsuccessful None
re.fullmatch(p, string, flag=0)

Detecting whether p and string matching full
return _sre the object, otherwise None
re.search(p, string, flag=0)

Scanning the first substring matching the search string
successful return re.Match object unsuccessful returns None, matched to the first stop
re.findall(p, string, flag=0)

Find full text matching substring all
return match to the list of sub-strings
re.finditer (p string flag = 0)

Iterator type of findall
re.sub(old, new, string, flag=0)

After the full-text search p replaced with new
re.split (delimiter, string, maxsplit = 0, flag = 0)

Divided
by delimiter string into the list type, maxsplit specified number of division
*re.purge()

Clear Cache Regular Expression
re.escape(pattern)

In addition to the ASCII, numerical model, characters _ escape outside, for example:
```
re.escape(r'www.baidu.com is good, i love')
# 'www\\.baidu\\.com\\ is\\ good,\\ i\\ love'
```