Python learning log for small y--variables

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Two. Python variables

(1) Definition of variables

Variable can store a specified range of values in a chunk of data in the computer's memory, and the value can be changed.

(2) Naming of variables

Variable names have letters, numbers, underscores

Number cannot start

You cannot use a keyword as a variable name

Chestnut: A A1 A_ a_1

(3) Assigning values to variables

Is the process of declaring and defining variables

A=1

ID (a)

Three. Operators and expressions

(1) Python operators include:

Assignment operators

' = ' equals: a=3,b= ' asdfgh '

' + = ' plus equals: a+=3

'-= ' minus equals: a-=3

' *= ' multiplied equals: a*=3

'/= ' except equals: a/=3

'%= ' to seek remainder equals: a%=3

Arithmetic operators

' + ' addition: a+b

'-' subtraction: A-B

' * ' Multiplication: a*b

'/' Real Division: 3/2 (different from 2.x version) 3.1/2

'//' integer division: 5.6/2 5.6//2

'% ' seeking remainder: 17%6=5

' * * ' power operation: 2**3=8

Relational operators

' < ' less than: 1<2

' > ' Greater than: 2>3

' <= ' less than equals: 2<=3

' >= ' greater than equals: ' 3>=2

'! = ' is not equal to: 1!=2

' = = ' is exactly equal to: 2==2

logical operators

' and ' logic with: True and False

' or ' logic or: True or False

' Not ' logical non: not True

Precedence of the operator:

　　　　

(2) Expression:

An expression is a formula that connects different data (including variables, functions) to certain rules with operational symbols.

(3) Practice

Arithmetic device

#Arithmetic
Import Sys
Running=true
While running:
    Try
        T=int (input ())
        P=int (input ())
    Except Eoferror:   #EOFError是什么?
        Break
    Print (' \ n ', t+p)
    Print (' \ n ', t-p)
    Print (' \ n ', t*p)
    Print (' \ n ', t/p)

Python learning log for small y--variables