How Python removes unwanted characters from a string

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Problem:

Filter the extra white space characters in the user input

' ++++abc123---'

Filter ' \ r ' in edit text under a Windows:

' Hello world \ r \ n '

Remove Unicode combination characters from text, tone

"Zhào Qián sūn lǐzhōu wúzhèng Wáng"

How to solve the above problem?

Remove both ends of the string: Strip (), Rstrip (), Lstrip ()

#!/usr/bin/python3 s = '-----abc123++++  ' # Remove empty characters on both sides of print (S.strip ()) # Delete left empty character print (S.rstrip ()) # Delete right empty character print ( S.lstrip ()) # Delete both sides-+ and Null characters print (S.strip (). Strip ('-+ '))

Delete a single fixed position character: Slice + splice

#!/usr/bin/python3 s = ' abc:123 ' # string stitching method to remove colon new_s = S[:3] + s[4:]print (new_s)

Delete any character at the same time delete many different characters: replace (), re.sub ()

#!/usr/bin/python3 # Remove the same character in string s = ' \tabc\t123\tisk ' Print (s.replace (' \ t ', ') ')  import re# Remove \r\n\t character s = ' \r\nabc\ T123\nxyz ' Print (Re.sub (' [\r\n\t] ', ' ', s))

Delete many different characters at the same time: translate () mapping for Str.maketrans () in Py3

#!/usr/bin/python3 s = ' abc123xyz ' # a _> x, b_> y, c_> Z, Character Map encrypt print (Str.maketrans (' abcxyz ', ' Xyzabc ')) # Translat e convert it to string print (S.translate (Str.maketrans (' abcxyz ', ' xyzabc ')))

Remove tones from Unicode characters

#!/usr/bin/python3 import Sysimport Unicodedatas = "Zhào qián sūn lǐzhōu wúzhèng wáng" remap = {# Ord returns the ASCII value ord (' \ t '): ', Ord (' \f '): ', Ord (' \ R '): None}# remove \ t, \f, \ra = s.translate (Remap) "" Constructs a dictionary by using the Dict.fromkeys () method, each Unicode and note as Key, for which the values are all none and then use Unicodedata.normalize () to normalize the original input to the exploded form character Sys.maxunicode: An integer that gives the value of the maximum Unicode code point,　　That is, 1114111 (16-0X10FFFF). Unicodedata.combining: Returns the canonical composition class assigned to the character Chr as an integer. If no composition class is defined, 0 is returned. "' cmb_chrs = Dict.fromkeys (c for C in range (Sys.maxunicode) if Unicodedata.combining (Chr (c))) #此部分建议拆分开来理解b = Unicodedat A.normalize (' NFD ', a) ' Call the Translate function to delete all the accent "print (b.translate (cmb_chrs))