Python beginner day2--(String (str) internal features introduction)

Introduction to str internal functions

1,pitalize (self): capitalize the first letter of the string

s = ' Hello '

result = S.capitalize ()

Print (Result) Result: Hello

2,casefold (self): see string becomes lowercase

s = ' HELLO '

result = S.casefold ()

Print (result) Result: Hello

3,center (self, Width, fillchar=none): Centered by string, padding by default with spaces

s = ' HELLO '

result = S.center (20, ' * ')

Print (Result) Result: *******hello********

4, COUNT (self, sub, Start=none, End=none): Counts the number of occurrences of a character in a string, and can be specified as the last position.

s = ' HELLO '

result = S.count (' L ')

Print (Result) results: 2

5, endswith (self, suffix, start=none, end=none): Determines whether a string has a character or end of a string, and can be specified as the last position.

s = ' HELLO '

result = S.endswith (' LO ')

RESULT1 = S.endswith (' LX ')

Print (Result) Result: True

Print (RESULT1) Result: False

6, Expandtabs (self, tabsize=8): Replaces the TAB key in a string with a space, the default 8 spaces

s = ' hello\tworld! '

result = S.expandtabs ()

RESULT1 = S.expandtabs (20)

Print (Result) Result: HELLO world!

Print (RESULT1) Result: HELLO world!

7, find (self, sub, Start=none, End=none): Finds a character or string in a string, returns a subscript if found, if not found-1

s = ' helloworldhello! '

result = S.find (' LO ')

RESULT1 = S.find (' LX ') print (Result) results: 3

Print (RESULT1) Results: 1

8, Index (self, sub, Start=none, End=none): Finds a character or string in a string, if it finds a return subscript, if no throw exception is found (error)

s = ' helloworldhello! '

result = S.index (' LO ')

Print (Result) results: 3

s = ' helloworldhello! '

RESULT1 = S.index (' LX ')

Print (RESULT1) The following results: Error content

Traceback (most recent): File "c:/python/test2.py", line 3, <module>

                                                                                               &NBSP;RESULT1 = S.index (' LX ')

Valueerror:substring not found

9, Format (self, *args, **kwargs): String formatting

s = ' Flowers '

Print (' This is {}! '). Format (s))

Print (' This is {0} flowers, which is {1} flowers '. Format (' Red ', ' yellow '))

Print (' Colour {name} and {name1} '. Format (name1 = ' yellow ', name = ' Red ')

Results:

This is flowers!

This is red flowers, which is yellow flowers

Colour red and yellow

Isalnum (self): Determine whether a string consists only of numbers and letters

s = ' flowers12 '

S1 = ' flowers12!! '

result = S.isalnum ()

RESULT1 = S1.isalnum ()

Print (Result) Result: True

Print (RESULT1) Result: False

One, Isalpha (self): Determines whether a string consists only of letters

s = ' Flowers '

S1 = ' FLOWERS12 '

result = S.isalpha ()

RESULT1 = S1.isalpha ()

Print (Result) Result: True

Print (RESULT1) Result: False

IsDigit (self): Determines whether a string is a number:

s = ' 1223 '

S1 = ' FLOWERS12 '

result = S.isdigit ()

RESULT1 = S1.isdigit ()

Print (Result) Result: True

Print (RESULT1) Result: False

Isdecimal (self): Determines whether a string is a decimal number

s = ' 1223 '

S1 = ' 0x1223 '

result = S.isdecimal ()

RESULT1 = S1.isdecimal ()

Print (Result) Result: True

Print (RESULT1) Result: False

Isidentifier (self): Determine if an identifier is valid

s = ' 12hello '

S1 = ' Hello '

result = S.isidentifier ()

RESULT1 = S1.isidentifier ()

Print (Result) Result: False

Print (RESULT1) Result: True

Islower (self): Determines whether a string is lowercase.

s = ' Hello '

S1 = ' Hello '

result = S.islower ()

RESULT1 = S1.islower ()

Print (Result) Result: False

Print (RESULT1) Result: True

Isidentifier (self): Determine if a string is numeric only

s = ' 1256 '

S1 = ' test1256 '

result = S.isnumeric ()

RESULT1 = S1.isnumeric ()

Print (Result) Result: True

Print (RESULT1) Result: False

17,isspace (self): Determines whether a string is a space

s = '

S1 = ' Test 1256 '

result = S.isspace ()

RESULT1 = S1.isspace ()

Print (Result) Result: True

Print (RESULT1) Result: False

18,istitle (self): Determines whether a string is a caption

s = ' Hello world '

S1 = ' Hello World '

result = S.istitle ()

RESULT1 = S1.istitle ()

Print (Result) Result: True

Print (RESULT1) Result: False

19,isupper (self): Determines whether a string is uppercase

s = ' HELLO '

S1 = ' Hello '

result = S.isupper ()

RESULT1 = S1.isupper ()

Print (Result) Result: True

Print (RESULT1) Result: False

20,join (self, iterable): Splits the argument (interable) with a string

s = ' HELLO '

result = S.join (' xxx** ')

Print (Result) Result: xhelloxhelloxhello*hello*

Ljust (self, width, fillchar=none) and rjust (self, width, fillchar=none) fills the specified width from left or right with the specified character

s = ' HELLO '

result = S.ljust (12, ' * ')

RESULT1 = S.rjust (12, ' * ')

Print (Result) Result: hello*******

Print (RESULT1) Result: *******hello

Lower (self) and upper: turns a string into lowercase and uppercase

s = ' HELLOworld '

result = S.lower ()

RESULT1 = S.upper ()

Print (Result) Result: HelloWorld

Print (RESULT1) Result: HELLOWORLD

Lstrip (self, Chars=none) and Rstrip (self, chars=none): Removes the specified character from the left or right

s = ' HELLOworld '

result = S.lstrip (' HE ')

RESULT1 = S.rstrip (' ld ')

Print (Result) Result: Lloworld

Print (RESULT1) Result: Hellowor

23,partition (Self, SEP): Splits a string into a tuple according to the specified character

s = ' HELLOworld '

result = s.partition (' wo ')

RESULT1 = s.partition (' ss ')

Print (Result) Result: (' HELLO ', ' wo ', ' rld ')

Print (RESULT1) Result: (' HELLOworld ', ' ', ')

Replace (self, old, new, Count=none): Replaces older characters with new characters, count specifies the number of overrides, default all overrides

s = ' Hello Word door '

result = S.replace (' o ', ' T ')

RESULT1 = S.replace (' o ', ' T ', 2)

Print (Result) Result: Hellt wtrd dttr

Print (RESULT1) Result: Hellt wtrd Door

25,split (self, Sep=none, maxsplit=-1): Divides a string with a pointing character into a list, and the specified character is automatically removed.

s = ' Helloworddoor '

result = S.split (' o ')

Print (Result) Result: [' hell ', ' w ', ' Rdd ', ' ', ' R ']

26,splitlines (self, keepends=none): Divides a string into a list by rows

s = "'

This is a cat

That's a dog

‘‘‘

result = S.splitlines ()

Print (Result) Result: [', ' This was a cat ', ' That's a dog ', ']

27,startswith (self, prefix, Start=none, End=none): Determines whether a string ends with a guided character.

s = ' HelloWorld '

result = S.startswith (' he ')

RESULT1 = S.startswith (' el ')

Print (Result) Result: True

Print (RESULT1) Result: False

Swapcase (self): Converts a string case to uppercase

s = ' HELLOworld '

result = S.swapcase ()

Print (Result) Result: HelloWORLD

29,title (self): Convert a string to a caption

s = ' This is a buautiful flowers '

result = S.title ()

Print (Result) Result: This is A buautiful Flowers

30,maketrans (self, *args, **kwargs) and Maketrans (self, *args, **kwargs): replace the corresponding character with the mapped situation, and the last parameter is to remove the character.

Python beginner day2--(String (str) internal features introduction)