String 02

Remove white space

>>> "    Remove left margin".lstrip()
'Remove left margin'
>>> "Remove white space on the right    ".rstrip()
'Remove white space on the right'
>>> "    Don't leave left and right blank    ".strip()
'Don't leave left and right blank'

Remove char characters

>>> "www.google.com".lstrip("wcom")
'.google.com'
>>> "www.google.com".lstrip(".wcom")
'google.com'
>>> "www.google.com".rstrip(".wcom")
'www.google'
>>> "www.google.com".strip(".wcom")
'google'
"strip Remove only the characters in parentheses"

Delete specific characters at the beginning and end

>>> "www.google.com".removeprefix("www.")
'google.com'
>>> "www.google.com".removesuffix(".com")
'www.google'

Split & splice
Split text before and after a specific flag

>>> "www.google.com".partition(".")
('www', '.', 'google.com')
>>> 'www.google.com/python'.rpartition('/')
('www.google.com', '/', 'python')
>>> 

Split text

>>> "At the beginning of human life, nature is good, nature is similar, and habits are far away".split()
['At the beginning of human life, nature is good, nature is similar, and habits are far away']
>>> "At the beginning of human life, nature is good, nature is similar, and habits are far away".split("，")
['The beginning of man', 'the theory of Mencius that men are born good', 'Sexual similarity', 'their habits become widely different']
>>> "At the beginning of human life, nature is good, nature is similar, and habits are far away".split("，",1)
['The beginning of man', 'The nature is good, the nature is similar, and the habit is far away']
>>> "At the beginning of human life, nature is good, nature is similar, and habits are far away".rsplit("，",1)
['At the beginning of man, nature is good and similar', 'their habits become widely different']

Split text by line

>>> "At the beginning of man,/n Nature is good,/n Similar in sex,/n their habits become widely different".splitlines()
['At the beginning of man,/n Nature is good,/n Similar in sex,/n their habits become widely different']
>>> "At the beginning of man,\n Nature is good,\n Similar in sex,\n their habits become widely different".splitlines()
['At the beginning of man,', 'Nature is good,', 'Similar in sex,', 'their habits become widely different']
>>> "At the beginning of man,\r Nature is good,\r Similar in sex,\r their habits become widely different".splitlines()
['At the beginning of man,', 'Nature is good,', 'Similar in sex,', 'their habits become widely different']

Splicing

>>> ".".join(['www','google','com'])
'www.google.com'
>>> '+'.join(('i','Love','U'))
'i+Love+U'

Two methods to copy the same text

>>> s='I Love U!'
>>> s+=s
>>> s
'I Love U!I Love U!'
>>> "".join(('I Love U!',"I Love U!"))
'I Love U!I Love U!'
"Adding is not as efficient as adding join Height of function"

Splicing

>>> year=1997
>>>> "My date of birth is{}".format(year)
'My date of birth is 1997'
>>> "1+1={},2*2={},3*3*3={}".format(1+1,2*2,3*3*3)
'1+1=2,2*2=4,3*3*3=27'
>>> "{}notice{}Very excited".format("vookii","cute girl")
'vookii I'm very excited to see Miss'
>>> "{1}notice{0}Very excited".format("vookii","cute girl")
'Little sister saw vookii Very excited'
>>> "{0}{0}{1}{1}".format("yes","wrong")
'right and wrong'
'I'm slag Hui. Martial brother will cut me'
>>> "I am{name}，It's a brother{act}".format(name="Zha Zha Hui",act="Cut me")
'I'm slag Hui. If I'm a brother, cut me'
"How to output{}"
>>> "{},{},{}".format('1','{}','3')
'1,{},3'
>>> "{},{{}},{}".format('1','3')
'1,{},3'
>>> 

value	meaning
'<'	Forces the string to align left within free space (default)
'>'	Forces the string to align right in free space
'='	Force padding to prevent the position after the symbol (if any) but before the number (this applies to printing strings as "+ 000000120")
'^'	Forces the string to be centered within free space

>>> "{:^}".format(123)
'123'
>>> "{:^10}".format(123)
'   123    '
>>> "{1:>10}{0:<10}".format(520,250)
'       250520       '
>>> "{left:>10}{right:<15}".format(right=520,left=250)
'       250520            '
>>> "{:010}".format(521)
'0000000521'
>>> "{:010}".format(-521)
'-000000521'
>>> "{1:%>10}{0:%<10}".format(520,250)
'%%%%%%%250520%%%%%%%'
>>> "{:0=10}".format(520)
'0000000520'

format string

value	meaning
'+'	Positive numbers are preceded by a positive sign (+) and negative numbers by a negative sign (-)
'-'	Only negative numbers are preceded by (-), the default behavior
Space	Positive numbers are preceded by a space, and negative numbers are preceded by a minus sign (-)

>>> "Add sign"
>>> "{:+} {:-}".format(520,-250)
'+520 -250'
>>>> "Set thousands"
'Set thousands'
>>> "{:,}".format(123456)
>>>> "{:_}".format(123456)
'123_456'

1. For floating-point numbers with [type] set to 'f' and 'f', it is to limit the number of digits displayed after the decimal point;
2. For floating-point numbers whose [type] is set to 'g' or 'g', it limits the total number of digits displayed before and after the decimal point;
3. For non numeric types, the limit is the size of the maximum field;
4. For integer type, the [. precision] option is not allowed.

>>> "{:.2f}".format(3.1415)
'3.14'
>>> "{:.2g}".format(3.1415)
'3.1'

>>> "{:.6}".format("I Love Python")
'I Love'
"For non numeric types, the limit is the size of the maximum field"
>>> "{:.2}".format(520)
Traceback (most recent call last):
  File "<pyshell#11>", line 1, in <module>
    "{:.2}".format(520)
ValueError: Precision not allowed in integer format specifier
"For integer types, use is not allowed[.precision]option"

value	meaning
'b'	Output parameters in binary form
'c'	Output parameters as Unicode characters
'd'	Output parameters in decimal form
'o'	Output parameters in octal form
'x' or 'x'	Output parameters in hexadecimal form
'n'	Similar to'd ', except that it is inserted in the appropriate position using the delimiter set by the current locale
None	Like'd '

>>> "{:b}".format(80)
'1010000'
>>> "{:c}".format(80)
'P'
>>> "{:d}".format(80)
'80'
>>> "{:o}".format(80)
'120'
>>> "{:x}".format(80)
'50'
"Front plus#Prompt for character base“
>>> "{:#b}".format(80)
'0b1010000'
>>> "{:#d}".format(80)
'80'
>>> "{:#o}".format(80)
'0o120'
>>> "{:#x}".format(80)
'0x50'

value	meaning
'e' or 'e'	Output the parameters in the form of scientific counting method (indicate the index with the letter 'e', and the default accuracy is 6)
'f' or 'f'	Output the parameters in the form of fixed-point representation ('not a number 'is marked with' nan ', infinity is marked with' inf ', and the default precision is 6)
'g' or 'g'	In general format, decimals are output in the form of 'f', and large numbers are output in the form of 'e'
'n'	Similar to 'g', the difference is that it will be inserted in the appropriate position using the separator set by the current locale
'%'	Output as a percentage (multiply the number by 100 and display as a fixed-point representation followed by a percentage sign)
None	Similar to 'g', the difference is that when using fixed-point representation, at least one digit will be displayed after the decimal point, and the default precision is consistent with the precision required for the given value

>>> "{:e}".format(3.1415)
'3.141500e+00'
>>> "{:f}".format(3.1415)
'3.141500'
>>> "{:g}".format(123456789)
'1.23457e+08'
>>> "{:g}".format(1234.56789)
'1234.57'
>>> "{:%}".format(0.85)
'85.000000%'
>>> "{:.2%}".format(0.85)
'85.00%'
>>> "{:.{gjz}%}".format(0.85,gjz=2)
'85.00%'

f-string

>>> year=1997
>>> f"My year of birth is{year}"
'My year of birth is 1997'
>>> f"1+1={1+1},2*2={2*2},3*3*3={3*3*3}"
'1+1=2,2*2=4,3*3*3=27'
>>> f"{-520:010}"
'-000000520'
>>> f"{123456789:,}"
'123,456,789'
>>> f"{3.1415:.2f}"
'3.14'