Python (5) string processing (Sub,replace,find,index,upper,strip)

One, the use of sub and replace

The Re.sub function takes a regular expression-based substitution work

Re.sub Replace with a, B or C in the target string and replace all

1>>>ImportRe2>>> Re.sub ('[ABC]','o','Mark')3 'Mork'4>>> Re.sub ('[ABC]','o','caps')5 'oops'6>>

Replace usage Description:

1>>>a2 'asds23dfg34'3>>> A.replace ('s','M')#Replace All4 'amdm23dfg34'5>>> B ='Adfafafafa'6>>> B.replace ('a','M', 3)#the substitution of the specified number7 'Mdfmfmfafa'

Second, the use of Find and Index

Index,find returns the subscript of the found string; If the returned value is not found, then-1, and index throws an exception directly

A.find (' t ', start) search from start position

A.find (' t ', start,end) search from the specified position

A.rfind (' t ') start search from the right position

A.count (' t ') how many specified characters are searched

1>>> A ='12432423'2>>> A.find ('1')3 04>>> A.find (5)5 Traceback (most recent):6File"<stdin>", Line 1,inch<module>7 typeerror:expected A character buffer object8>>> A.find (' -')91

1>>>a2 '12432423'3>>> f = a.find ('M')4>>>F5-16>>> f = a.find (' +')#returns the first position of a string7>>>F829>>> f = a.find ('435')Ten>>>F One-1

1 '12432423'2>>> A.index ('4')324>>> A.index ('8')5 Traceback (most recent):6File"<stdin>", Line 1,inch<module>7Valueerror:substring notfound8>>> f = a.index ('8')9 Traceback (most recent):TenFile"<stdin>", Line 1,inch<module> OneValueerror:substring notFound

Three, case processing, upper,lower,swapcase,capitalize,title

1>>>a2 '123dfsdfs'3>>> A ='asds23dfg34'4>>> A.upper ()#ALL caps5 'asds23dfg34'6>>> A.lower ()#All lowercase7 'asds23dfg34'8>>> A.swapcase ()#Case Exchange9 'asds23dfg34'Ten>>> a.capitalize ()#initials uppercase remaining lowercase One 'asds23dfg34' A>>>A.title () - 'asds23dfg34'          #substring, first letter uppercase ->>> the Keyboardinterrupt

Four, the use of strip

The strip in Python is used to remove the end and end characters of a string, so Lstrip is used to remove the left character, Rstrip to remove the right character.

Each of these three functions can pass in a parameter that specifies the first and last characters to be removed.

It is important to note that a character array is passed in , and the compiler strips out all the corresponding characters at both ends

1>>>a2 'asds23dfg34'3>>> A.strip ('a')4 'sds23dfg34'5>>> A.strip ('s')6 'asds23dfg34'7>>> s ='saaaay Yes No yaaaass'8>>> S.strip ('say')#Find them on both sides .9 'Yes No'                   #There's a space on each side .Ten>>> S.lstrip ('say')#just look to the left. One 'Yes No Yaaaass'         A>>> S.rstrip ('say')#just find the right . - 'saaaay Yes No'

Python (5) string processing (Sub,replace,find,index,upper,strip)