Operators in Python
Like every other programming language, Python has numerous operators. Some of those operators have similar functionalities in most
programming languages.
Operators can be categorized according to their functionality and the data type of the expression. These can be
categorized as below.
- Arithmetic Operator
- Relational Operator
- Logical Operator
- Assignment Operator
- Bitwise Operator
- Membership Operator
- Identity Operator
Now let's look into detail of each types of operators in Python.
Arithmetic Operators:
These operators are used in performing arithmetic operation like addition, subtraction, multiplication and division. These are also binary
operator
means it perform on two operands.
| Operator | Symbol | Description | Usage Example (in IDLE) |
|---|---|---|---|
| Addition | + | Adds two numbers or variables |
>>>5+10 15 OR (if a=5 and b= 10) >>> a + b 15 |
| Subtraction | - | Subtract two numbers or variables |
>>>10 - 5 5 OR (if a=5 and b= 10) >>> a - b 5 |
| Multiplication | * | Multiply two numbers or variabless |
>>>10 * 5 50 OR (if a=5 and b= 10) >>> a * b 50 |
| Division | / | Divide first operand by the second operand |
>>>10 / 5 2 OR (if a=50 and b= 10) >>> a / b 5 |
| Modulo | % | Divide first operand by the second Operand and return the remainder |
>>>10 % 5 0 OR (if a=50 and b= 8) >>> a % b 2 |
| Floor Division | // | Divide first operand by the second Operand and return the whole number without the decimal value. |
>>>22 // 7 3 OR (if a = 22 and b = 7) >>> a // b 3 |
| Exponent | ** | Raise the first operand to the power of second |
>>>3 ** 3 27 OR (if a = 4 and b = 2) >>> a ** b 16 |
Relational Operators:
These are the operators which compare the values of two operand and check the relation between them. These are also binary operator.
| Operator | Symbol | Description | Usage Example (in IDLE) |
|---|---|---|---|
| Equal to | == | Check two operand and return "True" if they are equal else will return "False" |
>>>3 == 3 True OR (if a=4 and b= 2) >>> a == b False |
| Not Equal to | != | Check two operand and return "True" if they are not equal else will return "False" |
>>>3 != 3 False OR (if a=4 and b= 2) >>> a != b True |
| Greater than | > | Check if the left operand is greater than right operand and return "True" else return "False |
>>>10 > 5 True OR (if a=8 and b= 18) >>> a > b False |
| Less than | < | Check if the left operand is smaller than right operand and return "True" else return "False |
>>>10 < 5 False OR (if a=8 and b= 18) >>> a < b True |
| Greater than or Equal to |
>= | Check if the left operand is greater than or equal to the right operand and return "True" else return "False |
>>>5 >= 5 True OR (if a=8 and b= 18) >>> a >= b False |
| Less than or Equal to |
<= | Check if the left operand is smaller than or equal to the right operand and return "True" else return "False |
>>>5 <= 5 True OR (if a=28 and b= 18) >>> a <= b False |
Logical Operators:
Like other language logical operator are also supported by the Python.
| Operator | Symbol | Description | Usage Example (in IDLE) |
|---|---|---|---|
| Logical AND | and | Return "True" only if both the left and right operand value are true else will return "False" |
(if a= true and b=false) >>>a and b False OR (if a= true and b=true) >>> a and b True |
| Logical OR | or | Return "True" if any of the left or right operand value are true else will return "False" |
(if a= true and b=false) >>>a or b True OR (if a= false and b=false) >>> a or b False |
| Logical NOT | NOT | Return the reverse of the logical state of the Operator. |
(if a= true and b= false) >>>not a False OR >>> not b True |
Logical operators works on the basis of a guided principle known as Truth Table. Below is the truth table for the same.
| Left operand (a) | Right operand (b) | a and b | a or b | NOT a | NOT b |
|---|---|---|---|---|---|
| True | False | FALSE | TRUE | FALSE | TRUE |
| False | True | FALSE | TRUE | TRUE | FALSE |
| True | True | TRUE | TRUE | FALSE | FALSE |
| False | False | FALSE | FALSE | TRUE | TRUE |
Bitwise Operator:
Bitwise operator are often used whenever there is the need of bit by bit calculation. For further explanation let us take two variables
a and b having values "127" and "111" respectively. Then their binary representation will be as below.
a = 0111 1111
b = 0110 1111
Now in the example section we will check the result of different types of bitwise operator on these variables.
| Operator | Symbol | Description | Usage Example (in IDLE) |
|---|---|---|---|
| Bitwise AND | & | This will return 1 only if bits of both operand will have value 1 at the same bit position else it returns 0. |
>>>a & b 111 |
| Bitwise OR | | | This will return 1 if bits of any of the operand have the value 1 at the same bit position else it returns 0. |
>>>a | b 127 |
| Exclusive OR (XOR) | ^ | This will return 1 if bits of the two operand are different else it will return 0 if bits of two operand are same. |
>>>a^b 16 |
| Ones Compliment | ~ | This will flip each bits of the operand and negate the value. |
>>> ~b -111 |
| Left Shift | << | This will change each bits of the left operand in the left direction by the number of times as mentioned in right operand. |
>>> a<<2 -111 (binary equivalent is 0001 1111 1100) |
| Right Shift | >> | This will change each bits of the left operand in the right direction by the number of times as mentioned in right operand. |
>>> a>>2 31 (binary equivalent is 0001 1111) |
Below is the truth table for the bitwise operator:
| Left operand (a) | Right operand (b) | a & b | a | b | a^b |
|---|---|---|---|---|
| 1 | 0 | 0 | 1 | 1 |
| 0 | 1 | 0 | 1 | 1 |
| 1 | 1 | 1 | 1 | 0 |
| 0 | 0 | 0 | 0 | 0 |
Assignment Operators:
Below are the different types of assignment operator as supported by the Python.
| Operator | Symbol | Description | Usage Example (in IDLE) |
|---|---|---|---|
| assign value | = | Assign the value of right operand to the left operand. |
>>> a = 90 >>> a 90 |
| add and assign | += | Adds the values of the left operand and right operand and assign the result to the left operand. |
>>> a = 100 >>> a += 20 >>> a 120 |
| subtract and assign | -= | Subtract the values of the left operand and right operand and assign the result to the left operand. |
>>> a = 100 >>> a -= 20 >>> a 80 |
| multiply and assign | *= | Multiply the values of the left operand and right operand and assign the result to the left operand. |
>>> a = 100 >>> a *= 2 >>> a 200 |
| divide and assign | /= | Divide the value of the left operand by the value of right operand and assign the result to the left operand. |
>>> a = 100 >>> a /= 2 >>> a 50 |
| modulo and assign | %= | Divide the value of the left operand by the value of right operand and assign the remainder to the left operand. |
>>> a = 16 >>> a %= 3 >>> a 1 |
| floor divide and assign | //= | Do the floor division and assign the result to the right operand. |
>>> a = 50 >>> a //= 6 >>> a 8 |
| exponent and assign | **= | Do the exponential calculation and assign the result to the left operand. |
>>> a = 4 >>> a **= 2 >>> a 16 |
Membership Operators:
This operator is used to test the membership of a data in a sequence like list, tuples or string.
| Operator | Symbol | Description | Usage Example (in IDLE) |
|---|---|---|---|
| In | in | Checks the occurance of a variable in the sequence and return "True" if variable is found else return "False" |
>>> x= "House in the Street" >>> y= "House" >>> z= "Flat" >>> y in x True >>> z in x False |
| Not In | not in | Checks the occurance of a variable in the sequence and return "True" if variable is not present else return "False" |
>>> x= "House in the Street" >>> y= "House" >>> z= "Flat" >>> y not in x False >>> z not in x True |
Identity Operators:
This operator checks and compare the memory location of the two variables.
| Operator | Symbol | Description | Usage Example (in IDLE) |
|---|---|---|---|
| Is | is | Checks the identity of the variables and return "True" in case of same identity else return "False" |
>>> x = "test" >>> id(x) 31716544 >>> id("test") 31716544 >>> x is "test" True >>> x*2 'testtest' >>> x*2 is "test" False |
| Not Is | is not | Checks the identity of the variables and return "True" in case of different identity else return "False" |
>>> x = "test" >>> id(x) 31716544 >>> id("test") 31716544 >>> x is not "test" False |
Operator's Precedence:
Operator precedence defines the order in which the mathematical expression will be evaluated. An operator with a higher precedence
will be evaluated first and the operator with the lowest precedence will operate last.The below table shows the operator arrangement
according to their precedence.
| Precedence | Operator description | Operator |
|---|---|---|
| Highest | Exponential | ** |
| Complement, Unary plus minus | ~, +, - | |
| Arithmetic (Except add and subtract) | *, /, %, // | |
| Add and Subtract | +, - | |
| Bitwise shift operator | >>, << | |
| Bitwise AND operator | & | |
| OR and XOR operator | |, ^ | |
| Relational operators -1 | <= , =>, > , < | |
| Relational operators -2 | ==, != | |
| Assignment operators | =, +=, -=, *=, /=, %=, **= | |
| Identity operators | is, is not | |
| Membership operators | in, not in | |
| Lowest | Logical operators | and, or, not |