Python Basic 2-operator

3. Operator 3.1 arithmetic operator

• Arithmetic operators are one of the operators
• is the symbol used to complete the basic arithmetic operation to handle the arithmetic

Operator	Describe	Instance
+	Add	10 + 20 = 30
-	Reducing	10-20 = 10
*	By	10 * 20 = 200
/	Except	10/20 = 0.5
//	Take the Divide	Returns the integer portion of the Division (quotient) 9//2 output result 4
%	Take the remainder	Returns the remainder of division 9% 2 = 1
**	Power	Also known as the Second party, the powers, 2 * * 3 = 8

• In Python, the * operator can also be used for strings, and the result is the result of repeating a specified number of strings.

In [1]: "-" * 50
OUT[1]: '----------------------------------------'

Precedence of arithmetic operators

• first multiplication , the sibling operator is calculated from left to right , and can be used () to adjust the priority of the calculation

Operator	Describe	Priority level
**	Power (highest priority)	High
* / % //	Multiply, divide, take remainder, divide evenly	In
+ -	addition, subtraction	Low

3.2 Comparison (relational) operators

Operator	Describe
==	Checks whether the values of the two operands are equal and, if so, the condition, which returns True
!=	Check that the values of the two operands are not equal , and if so, the condition is true
>	Checks whether the value of the left operand is greater than the value of the right operand, and if so, returns True
<	Checks whether the value of the left operand is less than the value of the right operand, and if so, returns True
>=	Checks whether the value of the left operand is greater than or equal to the value of the right operand, and if so, returns True
<=	Checks whether the value of the left operand is less than or equal to the value of the right operand, and if so, returns True

Python 2.x does not mean that you can also use the <> operator

! = in Python 2.x can also be used to judge not equal to

3.3 Logical operators

operator	logical expression	description
and	x and y	only the values of x and Y are true to return true otherwise as long as X or Y has a value of False, Returns False
or	x or y
not	not X	If X is true, return False if X is False, return True

3.4 Assignment operators

• In Python, use = To assign a value to a variable
• In arithmetic operations, Python also provides a series of assignment operators that correspond to arithmetic operators in order to simplify the writing of the Code.
• Note: spaces cannot be used in the middle of an assignment operator

Operator	Describe	Instance
=	Simple assignment operator	c = A + B assigns the result of the operation of A + B to c
+=	Addition assignment operator	c + = A is equivalent to C = C + A
-=	Subtraction assignment operator	C-= A is equivalent to C = c-a
*=	Multiplication assignment operator	C *= A is equivalent to C = c * A
/=	Division assignment operator	C/= A is equivalent to C = c/a
//=	Take the divisible assignment operator	C//= A is equivalent to C = c//A
%=	Modulo (remainder) assignment operator	C%= A is equivalent to C = c% A
**=	Power assignment operator	c = A is equivalent to C = C A

Precedence of the 3.5 operator

• The following table has the arithmetic precedence from highest to lowest order

Operator	Describe
**	Power (highest priority)
* / % //	Multiply, divide, take remainder, divide evenly
+ -	addition, subtraction
<= < > >=	Comparison operators
== !=	equals operator
= %= /= //= -= += *= **=	Assignment operators
Not OR and	logical operators

Python Basic 2-operator