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# Python: Operators

The operator is a symbol that performs certain operations.

Python provides the following set of operators

1. Arithmetic Operators
2. Relational Operators or Comparison Operators
3. Logical operators
4. Bitwise operators
5. Assignment operators
6. Special operators

### 1. Arithmetic Operators:

- =>Subtraction

* =>Multiplication

/ =>Division operator

% =>Modulo operator

// =>Floor Division operator

** >Exponent operator or power operator

Eg: test.py:

1) a=10
2) b=2
3) print('a+b=',a+b)
4) print('a-b=',a-b)
5) print('a*b=',a*b)
6) print('a/b=',a/b)
7) print('a//b=',a//b)
8) print('a%b=',a%b)
9) print('a**b=',a**b)

Output:

1) Python test.py or py test.py
2) a+b= 12
3) a-b= 8
4) a*b= 20
5) a/b= 5.0
6) a//b= 5
7) a%b= 0
8) a**b= 100

Eg:

1) a = 10.5
2) b=2
3)
4) a+b= 12.5
5) a-b= 8.5
6) a*b= 21.0
7) a/b= 5.25
8) a//b= 5.0
9) a%b= 0.5
10) a**b= 110.25

Eg:

10/2 =>5.0
10//2 =>5
10.0/2 =>5.0
10.0//2 =>5.0

Note:

We can use +,* operators for str type also.

If we want to use + operator for str type then compulsory both arguments should be str type only otherwise we will get error.

1) >>> "durga"+10
2) TypeError: must be str, not int
3) >>> "durga"+"10"
4) 'durga10'

If we use * operator for str type then compulsory one argument should be int and other argument should be str type.

2*"durga"
"durga"*2
2.5*"durga" ==>TypeError: can't multiply sequence by non-int of type 'float'
"durga"*"durga"==>TypeError: can't multiply sequence by non-int of type 'str'

+= >String concatenation operator
*= >String multiplication operator

### Relational Operators:

>,>=,<,<=

Eg 1:

1) a=10
2) b=20
3) print("a > b is ",a>b)
4) print("a >= b is ",a>=b)
5) print("a < b is ",a<b)
6) print("a <= b is ",a<=b)
7)
8) a > b is False
9) a >= b is False
10) a < b is True
11) a <= b is True

We can apply relational operators for str types also

Eg 2:

1) a="durga"
2) b="durga"
3) print("a > b is ",a>b)
4) print("a >= b is ",a>=b)
5) print("a < b is ",a<b)
6) print("a <= b is ",a<=b)
7)
8) a > b is False
9) a >= b is True
10) a < b is False
11) a <= b is True

Eg:

1) print(True>True) False
2) print(True>=True) True
3) print(10 >True) True
4) print(False > True) False
5)
6) print(10>'durga')
7) TypeError: '>' not supported between instances of 'int' and 'str'

Eg:

1) a=10
2) b=20
3) if(a>b):
4) print("a is greater than b")
5) else:
6) print("a is not greater than b")

Output: a is not greater than b

Eg:

1) 10<20 ==>True
2) 10<20<30 ==>True
3) 10<20<30<40 ==>True
4) 10<20<30<40>50 ==>False

### equality operators:

== , !=

We can apply these operators for any type even for incompatible types also

1) >>> 10==20
2) False
3) >>> 10!= 20
4) True
5) >>> 10==True
6) False
7) >>> False==False
8) True
9) >>> "durga"=="durga"
10) True
11) >>> 10=="durga"
12) False

Eg:

1) >>> 10==20==30==40
2) False
3) >>> 10==10==10==10
4) True

### Logical Operators:

and, or ,not

We can apply for all types.

For boolean types behaviour:

and ==>If both arguments are True then only result is True
or ====>If atleast one arugemnt is True then result is True
not ==>complement

True and False ==>False
True or False ===>True
not False ==>True

For non-boolean types behaviour:

0 means False
non-zero means True
empty string is always treated as False

x and y:

==>if x is evaluates to false return x otherwise return y

Eg:

10 and 20
0 and 20

If first argument is zero then result is zero otherwise result is y

x or y:

If x evaluates to True then result is x otherwise result is y

10 or 20 ==> 10
0 or 20 ==> 20

not x:

If x is evalutates to False then result is True otherwise False

not 10 ==>False
not 0 ==>True

Eg:

1) "durga" and "durgasoft" ==>durgasoft
2) "" and "durga" ==>""
3) "durga" and "" ==>""
4) "" or "durga" ==>"durga"
5) "durga" or ""==>"durga"
6) not ""==>True
7) not "durga" ==>False

### Bitwise Operators:

We can apply these operators bitwise.
These operators are applicable only for int and boolean types.
By mistake if we are trying to apply for any other type then we will get Error.

&,|,^,~,<<,>>

print(4&5) ==>valid
print(10.5 & 5.6) => TypeError: unsupported operand type(s) for &: 'float' and 'float'

print(True & True) ==>valid

& ==> If both bits are 1 then the only result is 1 otherwise result is 0
| ==> If at least one bit is 1 then the result is 1 otherwise result is 0
^ ==>If bits are different then the only result is 1 otherwise result is 0
~ ==>bitwise complement operator
1==>0 & 0==>1
<< ==>Bitwise Left shift
>> ==>Bitwise Right Shift

print(4&5) =>4
print(4|5)  =>5
print(4^5) =>1

 Operator Description & If both bits are 1 then only result is 1 otherwise result is 0 | If atleast one bit is 1 then result is 1 otherwise result is 0 ^ If bits are different then only result is 1 otherwise result is 0 ~ bitwise complement operator i.e 1 means 0 and 0 means 1 >> Bitwise Left shift Operator << Bitwise Right shift Operator

### bitwise complement operator(~):

We have to apply complement for total bits.

Eg: print(~5) ==>-6

Shift Operators:

<< Left shift operator

After shifting the empty cells we have to fill with zero

print(10<<2)==>40

>> Right Shift operator

After shifting the empty cells we have to fill with sign bit.( 0 for +ve and 1 for -ve)

print(10>>2) ==>2

We can apply bitwise operators for boolean types also

print(True & False) =>False
print(True | False) ==>True
print(True ^ False) =>True
print(~True) =>-2
print(True<<2) =>4
print(True>>2) =>0

### Assignment Operators:

We can use assignment operator to assign value to the variable.

Eg:
x=10

We can combine asignment operator with some other operator to form compound assignment operator.

Eg: x+=10 ====> x = x+10

The following is the list of all possible compound assignment operators in Python

+=
-=
*=
/=
%=
//=
**=
&=
|=
^=
>>=
<<=

Eg:

1) x=10
2) x+=20
3) print(x) ==>30

Eg:

1) x=10
2) x&=5
3) print(x) ==>0

### Ternary Operator:

Syntax:

x = firstValue if condition else secondValue

If condition is True then firstValue will be considered else secondValue will be considered.

Eg 1:

1) a,b=10,20
2) x=30 if a<b else 40
3) print(x) #30

Eg 2: Read two numbers from the keyboard and print minimum value

1) a=int(input("Enter First Number:"))
2) b=int(input("Enter Second Number:"))
3) min=a if a<b else b
4) print("Minimum Value:",min)

Output:

Enter First Number:10
Enter Second Number:30
Minimum Value: 10

Q. Program for minimum of 3 numbers

1) a=int(input("Enter First Number:"))
2) b=int(input("Enter Second Number:"))
3) c=int(input("Enter Third Number:"))
4) min=a if a<b and a<c else b if b<c else c
5) print("Minimum Value:",min)

Q. Program for maximum of 3 numbers

1) a=int(input("Enter First Number:"))
2) b=int(input("Enter Second Number:"))
3) c=int(input("Enter Third Number:"))
4) max=a if a>b and a>c else b if b>c else c
5) print("Maximum Value:",max)

Eg:

1) a=int(input("Enter First Number:"))
2) b=int(input("Enter Second Number:"))
3) print("Both numbers are equal" if a==b else "First Number is Less than Second Number" if
a<b else "First Number Greater than Second Number")

Output:

D:\python_classes>py test.py
Enter First Number:10
Enter Second Number:10
Both numbers are equal
D:\python_classes>py test.py
Enter First Number:10
Enter Second Number:20
First Number is Less than Second Number
D:\python_classes>py test.py
Enter First Number:20
Enter Second Number:10
First Number Greater than Second Number

### Special operators:

Python defines the following 2 special operators

1. Identity Operators
2. Membership operators

1. Identity Operators

We can use identity operators for address comparison.
2 identity operators are available
1. is
2. is not

r1 is r2 returns True if both r1 and r2 are pointing to the same object
r1 is not r2 returns True if both r1 and r2 are not pointing to the same object

Eg:

1) a=10
2) b=10
3) print(a is b) True
4) x=True
5) y=True
6) print( x is y) True

Eg:

1) a="durga"
2) b="durga"
3) print(id(a))
4) print(id(b))
5) print(a is b)

Eg:

1) list1=["one","two","three"]
2) list2=["one","two","three"]
3) print(id(list1))
4) print(id(list2))
5) print(list1 is list2) False
6) print(list1 is not list2) True
7) print(list1 == list2) True

2. Membership operators:

We can use Membership operators to check whether the given object present in the given collection.(It may be String,List,Set,Tuple or Dict)

in -> Returns True if the given object present in the specified Collection

not in -> Retruns True if the given object not present in the specified Collection

Eg:

1) x="hello learning Python is very easy!!!"
2) print('h' in x) True
3) print('d' in x) False
4) print('d' not in x) True
5) print('Python' in x) True

Eg:

1) list1=["sunny","bunny","chinny","pinny"]
2) print("sunny" in list1) True
3) print("tunny" in list1) False
4) print("tunny" not in list1) True

### Operator Precedence:

If multiple operators present then which operator will be evaluated first is decided by operator precedence.

Eg:

print(3+10*2) -> 23
print((3+10)*2) -> 26

The following list describes operator precedence in Python

() => Parenthesis
** => exponential operator
~,- => Bitwise complement operator,unary minus operator
*,/,%,// => multiplication,division,modulo,floor division
<<,>> => Left and Right Shift
& => bitwise An
^ => Bitwise X-OR
| => Bitwise OR
>,>=,<,<=, ==, != =>Relational or Comparison operators
=,+=,-=,*=... =>Assignment operators
is , is not => Identity Operators
in , not in => Membership operators
not => Logical not
and => Logical and
or => Logical or

Eg:

1) a=30
2) b=20
3) c=10
4) d=5
5) print((a+b)*c/d) 100.0
6) print((a+b)*(c/d)) 100.0
7) print(a+(b*c)/d) 70.0
8)
9)
10) 3/2*4+3+(10/5)**3-2
11) 3/2*4+3+2.0**3-2
12) 3/2*4+3+8.0-2
13) 1.5*4+3+8.0-2
14) 6.0+3+8.0-2
15) 15.0

"Python Operators With Example"

"Python Logical Operators"

"Arithmetic Operators In Python"

"Python Operator Vs"

"Bitwise Operators In Python"

"Assignment Operators In Python"

"Relational Operators In Python"

"Symbol In Python"