Python data type

Python data type Python provides 6 standard data types by default:

1. Number类型           数值类型2. String类型           字符串类型3. List类型             列表类型4. Tuple类型            元组类型5. Dict类型             字典类型6. Set类型              集合类型

1. Number type numeric classification: Altogether 4 kinds of small categories:

1. 整型       int        例：30    2. 浮点型     float      例：30.33. 布尔型     bool       例：True or False4. 复数       complex    例：6+8j

1. Integral type

Integral types include positive integers, 0, and negative integers.

There are 4 types of writing formats commonly used:

十进制：        范围：0-9二进制：        范围：0-1八进制：        范围：0-7十六进制：        范围：0-9A-F

2. Float type (i.e. decimal type)

2 formats for declaring floating-point types:

小数点方式：    变量 = 3.14科学计数法：    变量 = 314e-2

3. Boolean type

2 Ways to express a Boolean type:

True  表示对象为真False 表示对象为假

4. plural

The complete structure of the complex number:

(实数+虚数)    例：6+8j

Real numbers: All the values that exist in real life are real numbers.

Imaginary number: Numbers that are not real (the square of I is-1 as the basic unit), the number that does not exist

数学：i*2 = -1  i就是虚数的基本单身 1i，2i，3i...计算机中：用j来表示i即可

Two ways to declare a complex number:

表达式方式：    变量 = 实数 + 虚数 例：num = 3 + 4j特定功能：    变量 = complex(实数，虚数值) 例：num = complex(5,3)

2. String type (literal type) strings are commonly written in 6 ways:

1. 单引号字符串       例：‘Hello Word！‘2. 双引号字符串       例："Hello Word！"3. 三引号字符串       例：‘‘‘ Hello Word！‘‘‘4. 转义符字符串       例："This‘s a pen！" or ‘This\‘s a pen‘5. 自然字符串         例：r‘Hello Word！\n‘6. Unicode字符串     例：u‘Hello Word！‘

1. Single quotation marks: When the content contains a large number of double quotation marks, it is appropriate to use single quotation marks to declare the string 2. Double quotation marks: When the content contains a large number of single quotes, it is appropriate to use double quotation marks to declare the string 3. Three-quote: for multiple (row) content, single and double quotes are present in cases where the string is declared

Note: in general, use single quotes!

4. Escape character: Change the meaning of a string by some format

Common escape characters are as follows:

转义符            描述\(在行尾时)       续航符\\               反斜杠\‘               单引号\"               双引号\a               响铃\b               退格(Backspace)\e               转义\000             空\n               换行\v               纵向制表符\t               横向制表符\r               回车\f               换页\oyy             八进制数，yy代表字符    例：\o12代表换行\xyy             十六进制数，yy代表字符  例：\x0a代表换行\other           其他的字符以普通格式输出

5. Meta strings (i.e. natural strings)

Adding the letter R or R before any string, all escape characters in the current string are not escaped when used, and are common in regular expressions.

3. List Type

A list is a sequential combination of some data that can be arbitrarily modified and manipulated after the combination.

格式： 变量 = [值，值，值，...]标识符： []

How to create a list:

1. lie = list((1,2,4))2. lie = list([1,2,4])3. lie = [1,2,4]4. lie = list(tuple((1,23,4)))5. lie = list(tuple([1,23,4]))

4. Type of tuple

A tuple is a sequential combination of some data and cannot be modified after it is combined.

格式： 变量 = 值，值，值，... or 变量 = (值，值,值，...)标识符： ，

How to create a tuple:

1. tu = 1,2,4,2. tu = (1,3,4,)3. tu = tuple((1,2,3,))4. tu = tuple([1,2,3,])5. tu = tuple(list((1,3,4,)))6. tu = tuple(list([1,3,4,]))

5. Dict Type

A dictionary is a set of unordered data combinations that have a key-value mapping relationship, which can be modified and manipulated.

格式： 变量 = {键：值，键：值，...}标识符：{}

How to create a dictionary:

1. dic = {1:324,2:345}2. dic[1] = ‘3435‘      **注**： 指定key创建的字典，一次只能指定一个key3. dic = dict({1:324,2:345})

6. Set type

A collection is an unordered collection of data that can be modified after a combination, and is inherently free of duplicate data functionality.

格式： 变量 = {值1，值2，值3，...}标识符：{}

How to create a collection:

1. se = set(‘abc‘)         **注**：调用set()函数创建集合时，每次只能添加一个元素2. se = {‘a‘,‘b‘}

Python data type