Python operators

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What is an operator?

This chapter mainly explains Python’s operators. Let’s take a simple example 4 +5 = 9 . In the example, 4 and 5 are called operands, and "+" is called the operator.

The Python language supports the following types of operators:

• Arithmetic operators

• Comparison (relational) operators

• Assignment operator

• Logical operator

• Bitwise operator

• Member operator

• Identity operator

• Operator precedence

Next let us learn Python operators one by one.

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Python arithmetic operators

The following assumes that variable a is 10 and variable b is 20:

Operator	Description	Example
+	Add - Add two objects	a + b Output result 30
-	Subtract - Get a negative number or one number minus another number	a - b Output result-10
*	Multiplication - Multiply two numbers or return a string repeated several times	a * b Output result 200
/	Divide - x divided by y	b / a Output result 2
%	Modulo - Returns the remainder of division	b % a Output result 0
**	Power - Returns x raised to the yth power	a**b is 10 raised to the 20th power, and the output result is 100000000000000000000
//	Return the integer part of the quotient	9//2 Output result 4, 9.0//2.0 Output result 4.0

The following example demonstrates the operation of all arithmetic operators in Python:

Try it »

The above example output result:

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Python comparison operator

The following assumes that variable a is 10 and variable b is 20:

Operator	Description	Example
==	Equal - compare whether the objects are equal	(a == b) Return False.
!=	Not equal to - Compares whether two objects are not equal	(a != b) Returns true.
<>	Not equal to - Compares whether two objects are not equal	(a <> b) Returns true. This operator is similar to != .
>	Greater than - Returns whether x is greater than y	(a > b) Returns False.
<	Less than - Returns whether x is less than y. All comparison operators return 1 for true and 0 for false. These are equivalent to the special variables True and False respectively. Note the capitalization of these variable names.	(a < b) returns true.
>=	Greater than or equal to - Returns whether x is greater than or equal to y.	(a >= b) Returns False.
<=	Less than or equal to - Returns whether x is less than or equal to y.	(a <= b) returns true.

The following examples demonstrate the operation of all comparison operators in Python:

The output result of the above example:

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Python assignment operator

The following assumes that variable a is 10 and variable b is 20:

##%=modulo assignment operatorc % = a is equivalent to c = c % a##**=//=

The following examples demonstrate the operation of all assignment operators in Python:

Output result of the above example:

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Python bitwise operators

Bitwise operators treat numbers as binary to perform calculations. The bitwise operation rules in Python are as follows:

In the following table, variable a is 60 and b is 13.

Operator	Description	Example
=	Simple assignment operator	c = a + b The operation of a + b The resulting assignment is c
+=	Additional assignment operator	c += a is equivalent to c = c + a
-=	Subtractive 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
Power assignment operator	c **= a is equivalent to c = c ** a
Take integer division assignment operator	c //= a is equivalent to c = c // a

##|Bitwise OR operator: As long as one of the two corresponding binary bits is 1, the result bit will be 1. (a | b) The output result is 61, binary interpretation: 0011 1101##^~##<<Left shift operator: Each binary digit of the operand is shifted to the left by a certain number of bits, specified by the number on the right of "<<" The number of digits to move, the high bits are discarded, and the low bits are filled with 0s. a << 2 The output result is 240, binary interpretation: 1111 0000>>Right shift operator: " >>"All binary digits of the operand on the left are shifted to the right by a certain number of digits,">>"The number on the right specifies the number of digits to movea >> 2 The output result is 15, binary Explanation: 0000 1111

The following example demonstrates the operation of all bit operators in Python:

1 - The value of c is: 12

2 - The value of c is: 61

3 - The value of c is: 49

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Operator

Operator	Description	Instance
&	Bitwise AND operator: Two values ​​participating in the operation, if the two corresponding bits are 1, the result of the bit is 1, otherwise it is 0	(a & b) The output result is 12, binary interpretation : 0000 1100
Bitwise XOR operator: when two corresponding When the binary bits are different, the result is 1	(a ^ b) and the output result is 49. Binary interpretation: 0011 0001
bitwise Negation operator: Negate each binary bit of the data, that is, change 1 to 0, and change 0 to 1	(~a) The output result is -61, binary interpretation: 1100 0011, in a The two's complement form of a signed binary number.

Logical expressionDescriptionInstanceand x and yBoolean AND - if x is False, x and y returns False, otherwise it returns the calculated value of y. (a and b) returns 20. orx or yBoolean "or" - if x is non-zero, it returns the value of x, otherwise it returns the calculation of y value. (a or b) returns 10. notnot xBoolean "not" - If x is True, returns False. If x is False, it returns True. not(a and b) returns False

Output result of the above example:

The above example output Result:

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Python Member Operator

In addition to some of the above operators, Python also supports member operators. The test instance contains a series of members, including strings, lists or tuples. .

Operator	Description	Instance
in	Returns True if a value is found in the specified sequence, False otherwise.	x is in the y sequence, returns True if x is in the y sequence.
not in	Returns True if the value is not found in the specified sequence, False otherwise.	x is not in the y sequence, returns True if x is not in the y sequence.

The following example demonstrates the operation of all member operators in Python:

The above example output result:

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Python identity operator

Identity operator used to compare storage locations of two objects

##is notis not is to determine whether the two identifiers refer to different objectsx is not y, if id(x) is not equal to id(y).

The following example demonstrates the operation of all identity operators in Python:

The output result of the above example:

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Python operator precedence

The following table lists all operators from highest to lowest precedence:

Operator	Description	Instance
is	is is used to determine whether two identifiers refer to an object.	x is y, if id(x) is equal to id(y ), is returns the result 1
		is not Return result 1

##<= < > >=Comparison operators<> == !=Equal operator##= %= /= //= -= += *= ** =is is notin not innot or and

The following example demonstrates the operation of all operator precedence in Python:

The output result of the above example is:

Operations Symbol	Description
**	Index (highest priority)
~ + -	Bitwise flip, unary plus sign and minus sign (the last two methods are named +@ and -@)
* / % //	Multiplication, division, modulo and integer division
+ -	Addition and subtraction
>> < ;<	Right shift, left shift operator
&	bit'AND'
^ |	Bitwise operators
Assignment operator
Identity operator
Member operator
Logical operator