Python operators7.docx - Python operators last modified...

Python operators
last modified July 6, 2020
In this part of the Python programming tutorial, we cover Python
operators.
An operator is a special symbol which indicates a certain process
is carried out. Operators in programming languages are taken
from mathematics. Applications work with data. The operators are
used to process data.
In Python, we have several types of operators:
 Arithmetic operators
 Boolean operators
 Relational operators
 Bitwise operators
An operator may have one or two operands. An operand is one of
the inputs (arguments) of an operator. Those operators that work
with only one operand are called unary operators . Those who
work with two operands are called binary operators.
The + and - signs can be addition and subtraction operators as
well as unary sign operators. It depends on the situation.
>>> 2
2
>>> +2
2
>>>
The plus sign can be used to indicate that we have a positive
number. But it is mostly not used. The minus sign changes the
sign of a value.
>>> a = 1
>>> -a
-1
>>> -(-a)
1

Multiplication and addition operators are examples of binary
operators. They are used with two operands.
>>> 3 * 3
9
>>> 3 + 3
6
Python assignment operator
The assignment operator
=
assigns a value to a variable. In
mathematics, the
=
operator has a different meaning. In an
equation, the
=
operator is an equality operator. The left side of
the equation is equal to the right one.
>>> x = 1
>>> x
1
Here we assign a number to an
x
variable.
>>> x = x + 1
>>> x
2
The previous expression does not make sense in mathematics. But
it is legal in programming. The expression means that we add 1 to
the
x
variable. The right side is equal to 2 and 2 is assigned to
x
.
>>> a = b = c = 4
>>> print(a, b, c)
4 4 4
It is possible to assign a value to multiple variables.
>>> 3 = y
File "<stdin>", line 1
SyntaxError: can't assign to literal
This code example results in syntax error. We cannot assign a
value to a literal.
Python arithmetic operators
The following is a table of arithmetic operators in Python
programming language.

Symbo
l
Name
+
Addition
-
Subtraction
*
Multiplicatio
n
/
Division
//
Integer
division
%
Modulo
**
Power
The following example shows arithmetic operations.
arithmetic.py
#!/usr/bin/env python
# arithmetic.py
a = 10
b = 11
c = 12
add = a + b + c
sub = c - a
mult = a * b
div = c / 3
power = a ** 2
print(add, sub, mult, div)
print(power)
All these are known operators from mathematics.
$ ./arithmetic.py
33 2 110 4.0
100
There are three operators dealing with division.
division.py
#!/usr/bin/env python

# division.py
print(9 / 3)
print(9 / 4)
print(9 // 4)
print(9 % 4)
The example demonstrates division operators.
print(9 / 4)
This results in 2.25. In Python 2.x, the / operator was an integer
division operator. This has changed in Python 3. In Python 3, the /
operator returns a decimal number.
print(9 // 4)
The // operator is an integer operator in Python 3.
print(9 % 4)
The
%
operator is called the modulo operator. It finds the
remainder of division of one number by another.