Into the world of Python (v) data type 2. Strings (String)

Strings string

A set of quotation marks that can contain a collection of numbers, letters, symbols (non-special system symbols).

Such as:

Strval= "This is a test!" Strval1= ' This is a test! ' Strval2= "" "This is a test" ""

Sanchong quotation marks (docstring)

Python Sanchong quotation marks allow strings to span multiple lines, including literal line breaks, tabs, and other special characters.

The Sanchong quotation mark syntax consists of three consecutive single or double quotation marks.

#!/usr/bin/pythonpara_str = "" "This is a long string of made up ofseveral lines and non-printable characters such AsT AB (\ t) and they would show up the that's the displayed. Newlines within the string, whether explicitly given likethis within the brackets [\ n], or just a NEWLINE withinthe vari Able assignment'll also show up. "" " Print para_str;

When executing the above code, the following results are produced. Note how each special character is converted to the print form, one until the last line break between the string "up" closing the triple quotation mark. Also note that a newline occurs or that uses an explicit carriage return at the end of a line or its escape code (\ n):

This was a long string that was made up ofseveral lines and non-printable characters such astab () and they would show up That is when displayed. Newlines within the string, whether explicitly given likethis within the brackets [], or just a NEWLINE withinthe variabl E assignment'll also show up.

It is important to note that Python will consider the contents of the paired quotation marks to be the string content.

The following example will have a syntax error

Say= ' Let's Go ' File ' <stdin> ', line1 say= ' let ' s go ' ^ syntaxerror:invalid syntax

The right approach is

If you include only single quotes: use double quotation marks to include strings

If you enclose a single quotation mark, double quotation marks: use double quotation marks to enclose the string, and double quotes inside the string are escaped with the escape character \

Say= "Let ' s \" Go "

Escape character

The following table is a list of non-printable characters that are not escaped and can be represented by a backslash symbol.

The escape character is interpreted in a single-quote and double-quote string.

Reverse Slash Symbol	Hexadecimal Character	Describe
\a	0x07	Ringtones or alarms
\b	0x08	Backspace key
\cx		Control-x
\c-x		Control-x
\e	0x1b	Escape
\f	0x0c	Page change
\m-\c-x		Meta-control-x
\ n	0x0a	New Line
\nnn		octal notation, where N has a range of 0.7
\ r	0x0d	Enter
\s	0x20	Space
\ t	0x09	TAB key
\v	0x0b	Vertical tabulation
\x		Character X
\xnn		hexadecimal notation, where the range of n is from 0.9,A.F, or AF

String Special Operators

operator	Description	Example A= Hello B=python
+	Concatenation-increases the value on both sides of the operator	The value of a + B is Hellopython
*	Duplicate-Creates a new string that links multiple copies of the same string	The value of a*2 is-hellohello
[]	Slice-Specifies from the given index character	The value of a[1] is e
[:]	Range Slice-characters within a given range can be given three values, starting index, end index, step value End value before the index will be taken out Omit starting index, starting from 0 Omit end index, to end. If the index value is negative, the Step value from the end indicates that there is no interval between the number of strings taken when the slice range is taken, and the default value is 1 If the step value is negative, you can also indicate from right to left	A[1:4] is  , ell A[:4] has a value of Hell a[1:] The value is Ello a[-4:-1] has a value of Ello a[::2] Hlo
Inch	Member-Returns True if a character exists in the given string	H in a result value is 1
Not in	Member-Returns TRUE if the input character does not exist in the given string	M Not in a result value is 1
R/r	Raw string-disables the actual meaning of the escaped character. The syntax primitive string is exactly the same as the normal string, except for the original string operator, the letter "R", which precedes the quotation marks. In "R" can be lowercase (r) or capital letter (R), must be placed immediately before the first quotation mark.	Print R ' \ n ' printing \ n and print R ' \ n ' printing \ n

String formatting operations

The coolest feature of Python is the string format operator%. This operation is the only string that complements the C-language printf () series function function. The following is a simple example:

#!/usr/bin/pythonprint "My name is%s and weight is%d kg!"% (' Zara ', 21)

When executing the above code, the following results are produced:

My name is Zara and weight are kg!

The following is the complete, it can be used with the% symbol list:

format Symbols	Conversion
%c	Character
%s	formatted with the STR () string conversion
%i	Signed decimal integer
%d	Signed decimal integer
%u	unsigned decimal integers
%o	Eight-binary integers
%x	hexadecimal integers (lowercase letters)
%x	hexadecimal integers (uppercase letters)
%e	Index symbol (lowercase ' e ')
%E	Index symbol (uppercase "E")
%f	Floating point Real numbers
%g	Shorthand for%f and%e
%G	Shorthand for%f and%e

Other supported symbols and functions are shown in the following table:

symbols	function
*	Parameters specify width and precision
-	Align Left
+	Display symbols
<sp>	Leave a blank before a positive number
#	Add a leading 0 (' 0 ') or hexadecimal leading 0x "or" 0X ", depending on whether the" X "or" X "uses octal.
0	Add 0 (not spaces) from the left side of the keyboard
%	' percent ' to leave a word '% '
(VAR)	mapping variables (dictionary parameters)
M.N.	M is the smallest total width and n is the number that shows the number of digits after the decimal point (if appl)

Unicode string

In Python, ordinary strings are stored internally as 8-bit ASCII, while Unicode strings are stored as 16-bit Unicode. This makes a group of characters more diverse, including the special characters of most languages in the world. Restricting processing of Unicode strings

#!/usr/bin/pythonprint u ' Hello, world! '

When the above code is executed, the following results are produced:

Hello, world!.

As you can see, the Unicode string uses the prefix u, just like the original string using the prefix R

Into the world of Python (v) data type 2. Strings (String)