Python----------string

String * Number-------------print string number of times

"Echo" * 3 ' Echoechoecho '

　　

Strings are added--------------strings are joined together

s = ' Hello ' + ' world's ' Hello World '

String length---------------------len

Split: S.split

S.split () splits s by a space (including multiple spaces, tabs \t , newline characters, \n etc.) and returns all the segmented strings.

ine = "1 2 3 4  5" numbers = Line.split () print numbers[' 1 ', ' 2 ', ' 3 ', ' 4 ', ' 5 ']

"1,2,3,4,5" line.  Split(', ')numbers
[' 1 ', ' 2 ', ' 3 ', ' 4 ', ' 5 ']

Connection: S.join

s = ' S.join (numbers) ' 1 2 3 4 5 ' s = ', ' S.join (Numbers) ' 1,2,3,4,5 '

Replacement: S.replace

s = "Hello World" s.replace (' World ', ' python ') ' Hello python '

Case conversion:

The S.upper () method returns a new string that capitalizes all the letters in S.

The S.lower () method returns a new string that will all lowercase letters in s.

"Hello World". Upper () ' Hello world ' #这两种方法也不会改变原来s的值s = "Hello World" Print s.lower () print Shello Worldhello World

Remove extra spaces:

S.strip () returns a new string that removes extra spaces at both ends of S.

S.lstrip () returns a new string that is removed from the extra space that begins with S.

S.rstrip () returns a new string that removes the extra space at the end of S.

s = "  Hello World   " S.strip () ' Hello World '

Multi-line string:

Python uses a pair """ or ‘‘‘ to generate a multiline string:

A = "" "Hello world.it is a nice day." "" " Print Ahello world.it is a nice day.

When storing, we add a line break between two lines of characters‘\n‘

Use ()Or \To change the line:

When the code is too long or for the sake of aesthetics, there are two ways to convert a line of code to multiple lines of code:

• ()
• \

A = ("Hello, World.")    It ' s a nice day. "    My name is xxx") a "Hello, world." It ' s a nice day. My name is xxx "

"Hello, world."     " it ' s a nice day."     "My name is xxx"a
Hello, world. It ' s a nice day. My name is xxx "

Cast to String:

• str(ob)Coercion is ob converted into a string.
• repr(ob)is also coerced into a ob string.

The different points are as follows:

STR (1.1 + 2.2) ' 3.3 ' repr (1.1 + 2.2) ' 3.3000000000000003 '

Formatted string: Format ()

' {} {} {} '. Format (' A ', ' B ', ' C ') ' A B C '

You can specify the relative position of the incoming parameter with a number: ' {2} {1} {0} '. Format (' A ', ' B ', ' C ') ' C b a '

You can also specify the name of the incoming parameter: ' {color} {n} {x} '. Format (n=10, x=1.5, color= ' Blue ') ' Blue 10 1.5 '

Can be mixed together: ' {color} {0} {x} {1} '. Format (ten, ' foo ', x = 1.5, color= ' blue ') ' Blue 1.5 foo '

You can use {<field name>:<format>} to specify the format: from Math import pi ' {0:10} {1:10d} {2:10.2f} '. Format (' foo ', 5, 2 * pi) ' Foo
   5       6.28 ' specific rules are the same as in C.

You can also use the old-fashioned% method for formatting:
s = "Some numbers:" x = 1.34y = * is separated by a percent, enclosed in parentheses t = "%s%f,%d"% (s, x, y) t ' some numbers:1.340000, 2 '

　　

Python----------string