Python Learning Note Five: string methods

Common string constants:

string . Digits : Contains numbers 0~9 the string

string . Letters : Contains all letters (uppercase or lowercase strings, python3.0 , use string.ascii-letters instead)

string . Lowercase : A string containing all lowercase letters

string . Printable : A string containing all printable characters

string . Punctuation : A string that contains all the punctuation

string . Uppercase : A string containing all uppercase letters

1 ) Find : Finds a substring in a longer string, returns the leftmost index where the substring is located, and returns if not found - 1

>>>title = "Monty Python ' s Flying Circus"

>>>title.find (' Monty ')

0

>>>title.find (' Python ')

6

Accept the optional start and end points parameters:

>>>subject = ' $$$ Get rich now!!! $$$ '

>>>subject.find (' $$$ ', 1)

21st

>>>subject.find ('!!! ', 1,16)

-1

2 ) Join : Used to concatenate elements in a sequence, and must be a string, syntax format: Connector . Join ( string )

>>>seq = [' 1 ', ' 2 ', ' 3 ', ' 4 ', ' 5 ']

>>>sep = ' + '

>>>sep.join (seq)

' 1+2+3+4+5 '

>>>dir = ', ' usr ', ' bin ', ' env '

>>> '/'. Join (dir)

'/usr/bin/env '

3 ) Lower : Returns the lowercase letter of a string

>>> ' Trondheim Hammer Dance '. Lower ()

' Trondheim Hammer Dance '

>>>

>>>

>>> name = ' Gumby '

>>> names = [' Gumby ', ' Smith ', ' Jones ']

>>> if Name.lower () in Names:print ' Found it '

...

Found it

Title Conversion:

title method: Capitalize all the words in the first letter, while the other letters are lowercase

>>> "That's All Folks". Title ()

"That ' SAll folks"

>>>

Capword function:

>>>import string

>>>string.capwords ("That's All Folks")

"That ' sAll folks"

4 ) Replace : Returns the string after all occurrences of a string have been replaced, that is, the lookup substitution

>>> ' This was a test '. Replace (' is ', ' EEZ ')

' Theezeez a test '

5 ) Split : Join inverse method used to split a string into a sequence

>>> ' 1+2+3+4+5 '. Split (' + ')

[' 1 ', ' 2 ', ' 3 ', ' 4 ', ' 5 ']

6 ) Strip : Returns a string that strips both sides (with no interior) space (by default)

>>> ' internal whitespace krpt '. Strip ()

' Internalwhitespace krpt '

Specify delimiter:

>>> ' * * * SPAM * for * everyone!!! '. Strip (' *! ')

' spam* for * everyone '

7 ) Translate : Replacing portions of a string with only a single character, with the advantage that you can make multiple substitutions at the same time, before replacing it, you need to complete a conversion table and use string module's Maketrans function

>>>from String Import Maketrans

>>>table = Maketrans (' cs ', ' KZ ')

>>>len (table)

256

>>> ' This was an incredibletest '. Translate (table, ') # The second parameter is optional, specifying the character to be deleted

' Thizizaninkredibletezt '

Python Learning Note Five: string methods