python

Tutorial on the use of str (string) in python3

This article mainly introduces the operation summary of python3 to str (string). It is very detailed in this article. Let’s have a look at it if you need it.

S 5en__ function (append the string later)

s1 ='Hello'
s2 = s1.__add__(' boy!')
print(s2)

# Output: Hello boy!

S. S. S. S. S. S. S. S. S. S. S. S.

s1 = 'Hello'
result = s1.__contains__('He')
print(result)

# Output: True

S. S. S. S. S. S. S. S. S. S. S. S.

s1 = 'Hello'
s2 = 'How'
result = s1.__eq__(s2)
print(result)

# Output: False

__format__

# placeholder

__getattribute__

# placeholder

__getitem__

# placeholder

__getnewargs__

# placeholder

S = s = s = s = s = s

print('b'.__ge__('a'))

# Output: True

__gt__ (greater than)

print('b'.__ge__('a'))

# Output: True

__hash__

# placeholder

__iter__

s1 = 'Hello'
result = s1.__contains__('He')
print(result)

# Output: True

0

S 51en__ (return string length)

print('abc'.__len__())

# Output: 3

S 55en__ (less than or equal to)

print('b'.__le__('a'))

# Output: False

S 59en__ (less than)

s1 = 'Hello'
result = s1.__contains__('He')
print(result)

# Output: True

3

__mod__

s1 = 'Hello'
result = s1.__contains__('He')
print(result)

# Output: True

4

__mul__

s1 = 'Hello'
result = s1.__contains__('He')
print(result)

# Output: True

5

__new__

s1 = 'Hello'
result = s1.__contains__('He')
print(result)

# Output: True

6

__ne__

s1 = 'Hello'
result = s1.__contains__('He')
print(result)

# Output: True

7

__repr__

s1 = 'Hello'
result = s1.__contains__('He')
print(result)

# Output: True

8

__rmod__

s1 = 'Hello'
result = s1.__contains__('He')
print(result)

# Output: True

9

__rmul__

# placeholder

__sizeof__

# placeholder

S 95en__ (return to self)

print('abc'.__str__())

# Output: abc

capitalize(capital letters)

s = 'tom'
print(s.capitalize())

# Output: Tom

casefold (uppercase to lowercase)

s = 'TOM'
print(s.casefold())

# Output: tom

center (specify length and padding characters, center the content, and space for padding characters)

s = 'Tom'
print(s.center(20,'-'))

# Output: --------Tom---------

count(count the number of occurrences of a string, parameter 2: start position, parameter 3: end position)

s1 = 'Hello'
s2 = 'How'
result = s1.__eq__(s2)
print(result)

# Output: False

6

encode (encoding)

s1 = 'Hello'
s2 = 'How'
result = s1.__eq__(s2)
print(result)

# Output: False

7

endswith (second argument to determine whether a string ends with a character or string: start position, third argument: end position)

s1 = 'Hello'
s2 = 'How'
result = s1.__eq__(s2)
print(result)

# Output: False

8

expandtabs (convert 1 tab key to 7 Spaces)

s1 = 'Hello'
s2 = 'How'
result = s1.__eq__(s2)
print(result)

# Output: False

9

find (find the index position of a character or string, parameter 2: start position, parameter 3: end position)

s = 'Hello'
print(s.find('o'))
print(s.find('o',0,3)) # Unable to return -1

# Output: 4
# -1

format(string formatting/concatenation)

# placeholder

1

format_map

# placeholder

2

index (looking for the index position of a character or string, like find, if the character does not exist, an error is reported)

# placeholder

3

isalnum(whether letters or Numbers)

# placeholder

4

isalpha(whether letter or not)

# placeholder

5

isdecimal (whether it is a decimal number)

# placeholder

6

isdigit (whether it is a number)

# placeholder

7

isidentifier (whether identifier/variable name)

# placeholder

8

islower (all lowercase)

s = 'Hello'
print(s.islower())

# Output: False

isnumeric (whether it is a number)

# placeholder

0

isprintable(printable characters or not)

# placeholder

1

isspace (whether space or not)

# placeholder

2

istitle (whether to capitalize the title/the first letter of each word)

# placeholder

3

isupper (all uppercase)

# placeholder

4

join(concatenates the elements of a sequence to generate a new string with the specified characters)

# placeholder

5

ljust(specify length and fill characters, content left aligned, fill characters left blank as Spaces)

# placeholder

6

lower (all strings in lowercase)

# placeholder

7

lstrip(removes the character specified to the left of the string, defaults to space)

# placeholder

8

maketrans(create a conversion table for character mapping, used in conjunction with the translate function)

# placeholder

9

partition (specify the separator to split the string)

# placeholder

0

replace(replace old (the old string) in the string with new(the new string), and if the third parameter max is specified, replace it no more than max times.)

# placeholder

1

rfind(looks for the location where the specified string appears from the right, and returns -1 if there is no match)

# placeholder

2

rindex(find the location where the specified string appears from the right, and report an error if there is no match)

# placeholder

3

rjust(specifies length and padding characters, right-aligned content, padding characters left blank as Spaces)

# placeholder

4

rpartition (specify the delimiter to split the string from the right)

# placeholder

5

rsplit(specify the separator to slice the string, if the second parameter num is specified, num is separated only once, and 1 list is returned)

# placeholder

6

rstrip(removes the specified character at the end of the string, defaults to space)

s = '!!! I am Tom !!!'
print(s.rstrip('!'))

# Output: !!! I am Tom

split(specify the delimiter to slice the string, if the second parameter num is specified, num is separated only once, and 1 list is returned)

s = 'a b c d'
print(s.split())
print(s.split(' ',2)) # Start on the left and space it twice

# Output: ['a', 'b', 'c', 'd']
# ['a', 'b', 'c d']

splitlines(returns 1 list, delimited by newline)

# placeholder

9

startswith (second argument to determine whether a string begins with a character or string: start position, third argument: end position)

# placeholder

0

strip(specified characters before and after deletion of string, default to space)

# placeholder

1

swapcase (case interchange)

# placeholder

2

title(converted to title, which is the first letter of each word in uppercase)

# placeholder

3

translate (character substitution according to the table created by the maketrans method)

# placeholder

4

upper(lowercase to uppercase)

# placeholder

5

zfill(specifies the length of the string. Align the original string to the right, fill in 0 in front)

s = 'Hello'
print(s.zfill(10))

#  Output: 00000Hello

conclusion