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A, String
String is immutable objects, so any operation will not have any impact on the original string.
Immutable objects There are four: str, int, BOOL, tuple
1, slice and the index
1.1 index, the index is down superscript, subscript 0 from the beginning.
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# S1 = "Chinese"
# Print (len (s1 )) of the length of the string # 2
# Print (S1 [0]) in #
# Print (S1 [. 1]) # State
# Print (S1 [-1]) # State reciprocal of
# Print (S1 [-2] ) #, the penultimate
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1.2 slice, may be used to intercept the content index of the string.
syntax: STR [start: end]
rule: care regardless tail, taken beginning at start, to the end position of interception but not including the End
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S2 = " I want to learn the Python "
Print (S2 [0: 3]) # acquires from 0 to 3, excluding 3.
# From 2 get to 5, excluding 5 results: learn Py
Print (s2 [4:]) # from April to the end, the result is: ython
Print (s2 [:]) # scratch get to the final result: I want to Learn the Python
Print (S2 [-1: -5]) # acquired from -1 to -5 this is to obtain any results of
Print (S2 [-5: -1]) # acquired from -5 to -1, the result : ytho
Print (s2 [-5:]) # get from -5 to final results: ython
Print (s2 [: - 1]) # this is to get to the last, and result: I want to learn Pytho
Print (s2 [1: 5: 2]) # from the first beginning to take, get to the fifth, every 2 to take a result: to P
Print (S2 [: 5: 2]) # from the beginning to the fifth , each take a two results: I learn Y
Print (S2 [:: 2. 4]) #4 taken from the beginning to the end, each take a two results: yhn
Print (S2 [-5 :: 2]) # from the penultimate 5 starts to take, get to the end, each of the two take a result: yhn
Print (S2 [-1: -5: -1]) # countdown from a first to take the reciprocal of the fifth, the values from right to left, the results: noht
Print (S2 [-5 :: -. 3]) # taken from the beginning to the penultimate 5, taken every 3 a, the result is: y for a
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step: if it is positive, taken from left to right. If it is negative, it is taken from right to left, the default is 1.
Slice syntax:
STR [Start: end: STEP]
Start: start position
end: end position
step: step
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' ''
2, case and turn
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S1 = " Hello World! "
RET = s1.capitalize () # capitalized
Print (s1) # the Hello world!
(RET) # the Hello world!
RET = s1.lower () # all converted to lowercase
Print (RET) # the Hello world!
RET = s1.upper () # all converted to uppercase
Print (RET) # HELLO WORLD!
RET = s1 .swapcase () # case interchangeable
Print (RET) # HELLO WORLD!
s1 = " the Hello, world "
RET = s1.title () # each separated by a special character letters capitalized
Print (RET) # the Hello , World
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. 3, cut to cut
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S1= " Chinese "
RET = s1.center (10, " * " ) # stretched to 10, the intermediate discharge the original string, the remaining positions up *
Print (RET) # **** **** China
S1 = " China \ t good "
Print (s1) # Chinese good
Print (s1.expandtabs ()) # can change the \ length t, change the default length of 8 results: Chinese good
s1 = " the Hello world "
RET = s1.strip ( ) # remove space around ends
Print (RET) # Hello World
RET = s1.lstrip () #Removing spaces left
Print (RET) # Hello World
RET = s1.rstrip () # strips spaces to the right of
Print (RET) # Hello World
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. 4, the replacement string Replace ()
' ''
S1 = " apple_banana_orange_strawberry "
RET s1.replace = ( " Orange " , " orange " )
Print (RET) # apple_banana_ orange _strawberry
RET = s1.replace ( " _ " , " # " , 2) #To replace _ #, replacing 2
Print (RET) # Apple Banana # # orange_strawberry
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. 5, a cutting string Split ()
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S1 = " apple_banana_orange_strawberry "
RET = s1.split ( " _ " )
Print ( RET) # [ 'Apple', 'Banana', 'Orange', 'Strawberry']
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. 6, the strings together the Join ()
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LST = [ ' Apple ' , ' Banana ' , ' Orange ' , 'Strawberry ' ]
court= ' , ' .Join (LST)
Print (RET) # Apple, Banana, Orange, Strawberry
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. 7, startsWith () determines whether the beginning ...
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S1 = " Apple "
RET = s1.startswith ( ' a ' ) # determines whether to begin a
Print (RET) # True
RET = s1.endswith ( ' E ' ) # determines whether to end h
Print (RET) # True
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. 8, the count cOUNT ()
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s1 = "Banana "
RET = s1.count ( " a " ) # lookups occur a
Print (RET) # . 3
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. 9, lookup index find () and index ()
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S1 = " Banana "
RET = S1. Find ( " a " ) # find a number of index
Print (RET) # . 1
RET = s1.find ( " m " ) # not found, return -1
Print (RET) # -1
RET = s1.index ( "a") # Find a number of index
Print (RET) # . 1
# RET = s1.index ( "m") # not found error: a ValueError: Not found the substring
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10, isdigit () determines whether a digital
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S1 = " 1234 "
RET = s1.isdigit ()
Print (RET) # True
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. 11, the length len of the string ()
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S1 = " Hello World "
RET = len (S1)
Print (RET) # 11
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12, the string is iterables
' ''
s1 = "World Hello "
for I in S1:
Print (I)
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Print Results:
H
E
L
L
O
W
O
R & lt
L
D
' ''