OPERATORS

Python - OPERATORS

Operators are used to perform operations on variables and values.

Types of Operators :

Arithmetic operators

Assignment operators

Comparison/Relational operators

Logical operators

Identity operators

Membership operators

Bitwise operators

ARITHMETIC OPERATORS :

Operator	Name	Example
+	Addition	x + y
-	Subtraction	x - y
*	Multiplication	x * y
/	Division	x / y
%	Modulus	x % y
**	Exponentiation	x ** y
//	Floor division	x // y

Python 3.6.6 (v3.6.6:4cf1f54eb7, Jun 27 2018, 03:37:03) [MSC v.1900 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> X=4
>>> Y=8
>>> X+Y (Addition)
12
>>> X-Y (Subtraction)
-4
>>> X//Y (Floor/truncate division - In this it removes digits after decimal and reviews the result)
0
>>> X*Y (Multiplication)
32
>>> X%Y (Modulus - In this division remainder is displayed as a result)
4
>>> X/Y (division)
0.5
>>> X**Y (exponential)
65536

Assignment Operators :

Operator	Description
=	It assigns the the value of the right expression to the left operand

Python 3.6.6 (v3.6.6:4cf1f54eb7, Jun 27 2018, 03:37:03) [MSC v.1900 64 bit (AMD64)] on win32
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>>> x=5
>>> x
5
>>> x=66.5
>>> print(x)
66.5

Operator	Description
+=	It increases the value of the left operand by the value of the right operand and assign the modified value back to left operand

Python 3.6.6 (v3.6.6:4cf1f54eb7, Jun 27 2018, 03:37:03) [MSC v.1900 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.

>>> a=25
>>> b=25
>>> a+=b
>>> print(a)
50
>>> a=a+b
>>> print(a)
75

Operator	Description
-=	It decreases the value of the left operand by the value of the right operand and assign the modified value back to left operand

Python 3.6.6 (v3.6.6:4cf1f54eb7, Jun 27 2018, 03:37:03) [MSC v.1900 64 bit (AMD64)] on win32
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>>> a=20
>>> b=10
>>> a-=b
>>> print(a)
10
>>> a=a-b
>>> print(a)
0

Operator	Description
*=	It multiplies the value of the left operand by the value of the right operand and assign the modified value back to left operand.

Python 3.6.6 (v3.6.6:4cf1f54eb7, Jun 27 2018, 03:37:03) [MSC v.1900 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> a=10
>>> b=20
>>> a*=b
>>> print(a)
200
>>> a=a*b
>>> print(a)
4000

Operator	Description
%=	It divides the value of the left operand by the value of the right operand and assign the reminder back to left operand.

Python 3.6.6 (v3.6.6:4cf1f54eb7, Jun 27 2018, 03:37:03) [MSC v.1900 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> a=20
>>> b=10
>>> a%=b
>>> print(a)
0
>>> a=a%b
>>> print(a)
0

Operator	Description
**=	a=b will be equal to a=ab, for example, if a = 4, b =2, a=b will assign 42 = 16 to a.

Python 3.6.6 (v3.6.6:4cf1f54eb7, Jun 27 2018, 03:37:03) [MSC v.1900 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> a=4
>>> b=2
>>> a**=b
>>> print(a)
16
>>> a=a**b
>>> print(a)
256

Operator	Description
//=	A//=b will be equal to a = a// b, for example, if a = 4, b = 3, a//=b will assign 4//3 = 1 to a.

Python 3.6.6 (v3.6.6:4cf1f54eb7, Jun 27 2018, 03:37:03) [MSC v.1900 64 bit (AMD64)] on win32
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>>> a=4
>>> b=3
>>> a//=b
>>> print(a)
1
>>> a=a//b
>>> print(a)
0

RELATIONAL/COMPARISONAL OPERATORS :

Comparison operators are used to comparing the value of the two operands and returns boolean true or false accordingly.

Operator	Description
==	If the value of two operands is equal, then the condition becomes true.
!=	If the value of two operands is not equal then the condition becomes true.
<=	If the first operand is less than or equal to the second operand, then the condition becomes true.
>=	If the first operand is greater than or equal to the second operand, then the condition becomes true.
<>	If the value of two operands is not equal, then the condition becomes true.
>	If the first operand is greater than the second operand, then the condition becomes true.
<	If the first operand is less than the second operand, then the condition becomes true.

Python 3.6.6 (v3.6.6:4cf1f54eb7, Jun 27 2018, 03:37:03) [MSC v.1900 64 bit (AMD64)] on win32
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(Equal condition example):
>>> a=5
>>> b=5
>>> a==b
True
>>> a=6
>>> b=7
>>> a==b
False

(Not equal condition):
>>> a=2
>>> b=3
>>> a!=b
True

(Less than or equals to):
>>> a=2
>>> b=4
>>> a<=b
True
>>> a=5
>>> b=5
>>> a<=b
True
>>> a=8
>>> b=2
>>> a<=b
False

(Greater than or equals to):
>>> a=8
>>> b=9
>>> a>=b
False
>>> a=78
>>> b=58
>>> a>=b
True
>>> a=88
>>> b=88
>>> a>=b
True

(Greater than condition):
>>> a=28
>>> b=11
>>> a>b
True

(Less than condition):
>>> a=5
>>> b=6
>>> a<b
True

LOGICAL OPERATORS :

These operators are used to combine the conditional statements.

Operator	Description
and	If both the expression are true, then the condition will be true. If a and b are the two expressions, a → true, b → true => a and b → true.
or	If one of the expressions is true, then the condition will be true. If a and b are the two expressions, a → true, b → false => a or b → true.
not	If an expression a is true then not (a) will be false and vice versa.

Python 3.6.6 (v3.6.6:4cf1f54eb7, Jun 27 2018, 03:37:03) [MSC v.1900 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> 5>6 and 4==4 ('and' condition)
False
>>> 5<6 and 5==5
True
>>> 2==2 or 5>6 ('or' condition)
True
>>> 1.5>1 or 2==2
True
>>> 5>9 or 2==3
False
>>> not 2==2 ('not' condition)
False
>>> not(2>1)
False

IDENTITY OPERATORS :

Identity operators are used to compare the objects, not if they are equal, but if they are actually the same object, with the same memory location.

Operator	Description
is	Returns true if both variables are the same object.
is not	Returns true if both variables are not the same object.

Python 3.6.6 (v3.6.6:4cf1f54eb7, Jun 27 2018, 03:37:03) [MSC v.1900 64 bit (AMD64)] on win32
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>>> x={1,2,3,4}
>>> y={1,2,3,4}
>>> z = x
>>> print(x is y)
False
>>> print(z is x)
True
>>> print(x is z)
True
>>> print(x is not z)
False
>>> print(x is not y)
True
>>> print(z is not x)
False

MEMBERSHIP OPERATORS :

Membership operators are used to test the membership of value inside a data structure. If the value is present in the data structure, then the resulting value is true otherwise it returns false.

Operator	Description
in	It is evaluated to be true if the first operand is found in the second operand.
not in	It is evaluated to be true if the first operand is not found in the second operand.

Python 3.6.6 (v3.6.6:4cf1f54eb7, Jun 27 2018, 03:37:03) [MSC v.1900 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> X={"apple","cherry","kiwi"}
>>> print("banana" in X)
False
>>> print("kiwi"in X)
True
>>> print("dragon fruit"not in X)
True
>>> print("orange"not in X)
True
>>> print("orange"not in X)

BITWISE OPERATORS :

Bitwise operators are used to compare binary numbers

Operator	Name	Description
&	AND	Sets each bit to 1 if both bits are 1
	OR	Sets each bit to 1 if one of two bits is 1
^	XOR	Sets each bit to 1 if only one of two bits is 1
~	NOT	Inverts all the bits
<<	Zero fill left shift	Shift left by pushing zeros in from the right and let the leftmost bits fall off
>>	Signed right shift	Shift right by pushing copies of the leftmost bit in from the left, and let the rightmost bits fall off

OPERATOR PRECEDENCE :

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

Operator	Description
**	The exponent operator is given priority over all the others used in the expression.
~,-,+	The negation, unary plus and minus.
* / % //	The multiplication, divide, modules, reminder, and floor division.
+ -	Binary plus and minus
>> <<	Left shift and right shift
&	Binary and.
^
<=, <, >, >=	Comparison operators (less then, less then equal to, greater then, greater then equal to).
<>, ==, !=	Equality operators.
=, %=, /=, //=, -=, +=,=,*=	Assignment operators
is is not	Identity operators
in not in	Membership operators
not or and	Logical operators