"Python" Python and regular re are the main methods used to enumerate

"Directly on the code"

#coding =utf-8
#1, first compile the string form of the regular expression into a pattern instance

#2, using the pattern instance to process text and get matching results

#3, finally get the message using the match instance, and do other things

Import re

# "1" Re.compile (String[,flag]) compiles regular expressions into pattern objects

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# "2" Re.match (Pattern,string[,flags])
# try to match pattern starting at the beginning of the input parameter string
# encounters an unmatched character or has reached the end of a string, returns none immediately, and instead gets the result of the match

#将正则表达式编译成pattern对象
Pattern = Re.compile (R ' \d+ ')
#使用re. Match matches the text, gets the match result, cannot match when will return none
RESULT1 = Re.match (pattern, ' 192abc ')
If RESULT1:
Print Result1.group ()
Else
print ' Match failed 1 '
RESULT2 = Re.match (pattern, ' abc192 ')
If RESULT2:
Print Result2.group ()
Else
print ' Match failed 2 '
#输出结果--------> 192 match failed 2 resul2 match when encountering a does not match, immediately return none
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# "3" Re.search (Pattern,string[,flags])
The #match () function matches only from the beginning of the string
#search () scans the entire string lookup match

#将正则表达式编译成pattern对象
Pattern = Re.compile (R ' \d+ ')
#使用re. Search matches the text to get a matching result that will not match when none is returned
RESULT1 = Re.search (pattern, ' abc192def ')
If RESULT1:
Print Result1.group ()
Else
print ' Match failed 1 '
#运行结果--------> 192
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# "4" Re.split (Pattern,string[,maxsplit])
#按照能够匹配的子串将string分割后返回 List
#maxsplit用于指定最大分割次数, if not specified, all will be split
Pattern = Re.compile (R ' \d+ ')
Print re.split (pattern, ' a1b2c3d4 ')
#运行结果-----------> [' A ', ' B ', ' C ', ' D ', ']
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# "5" Re.findall (Pattern,string[,flags])
#搜索整个string, returns all substrings that can be matched in the form of a list
Pattern = Re.compile (R ' \d+ ')
Print Re.findall (pattern, ' a1b2c3d4 ')
#运行结果----------> [' 1 ', ' 2 ', ' 3 ', ' 4 ']
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# "6" Re.finditer (Pattern,string[,flags])
#搜索整个string, returns all match objects that can be matched in the form of an iterator
Pattern = Re.compile (R ' \d+ ')
Matchiter = Re.finditer (pattern, ' a1b2c3d4 ')
For match in Matchiter:
Print Match.group ()
#运行结果------>
# 1
# 2
# 3
# 4
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'
# "7" Re.sub (Pattern,repl,string[,count])
#使用repl替换string中每一个匹配的子串后返回替换后的字符串.
#当repl是一个字符串时, you can use \id or \g<id>, \g<name> reference grouping, but you cannot use number 0.
#当repl是一个方法时, this method should only accept one parameter (the match object) and return a string to replace (the returned string cannot be referenced in a group)
#count用于指定最多替换的次数, replace all
P = When not specified Re.compile (R ' (? p<word1>\w+) (? p<word2>\w+) ') #使用名称引用
s = ' I say, hello world! '
Print p.sub (R ' \g<word2> \g<word1> ', s)
P = re.compile (R ' (\w+) (\w+) ') #使用编号
Print p.sub (R ' \2 \1 '), s)
def func (m):
return M.group (1). Title () + ' + m.group (2). Title ()
Print p.sub (func,s)
#输出结果------>
# Say I, World hello!
# Say I, World hello!
# I Say, Hello world!
'

# "8" Re.subn (Pattern,string[,count])
#返回 (Sub (Repl,string[,count]), number of replacements).
s = ' I say, hello world! '
p = re.compile (R ' (\w+) (\w+) ')
Print p.subn (R ' \2 \1 ', s)
def func (m):
return M.group (1). Title () + "+ m.group (2)." Title ()
Print P.subn (func,s)
#运行结果-------->
# (' Say I, World hello! ', 2)
# (' I Say, Hello world! ', 2)

"Python" Python and regular re are the main methods used to enumerate