Foundations Updated 2026-09 View as Markdown

Basic Operators

This section explains how to use basic operators in Python.

This section explains how to use basic operators in Python.

Arithmetic Operators#

Just as any other programming languages, the addition, subtraction, multiplication, and division operators can be used with numbers.

number = 1 + 2 * 3 / 4.0
print(number)

Try to predict what the answer will be. Does python follow order of operations?

Another operator available is the modulo (%) operator, which returns the integer remainder of the division. dividend % divisor = remainder.

remainder = 11 % 3
print(remainder)

Using two multiplication symbols makes a power relationship.

squared = 7 ** 2
cubed = 2 ** 3
print(squared)
print(cubed)

Using Operators with Strings#

Python supports concatenating strings using the addition operator:

helloworld = "hello" + " " + "world"
print(helloworld)

Python also supports multiplying strings to form a string with a repeating sequence:

lotsofhellos = "hello" * 10
print(lotsofhellos)

Using Operators with Lists#

Lists can be joined with the addition operators:

even_numbers = [2,4,6,8]
odd_numbers = [1,3,5,7]
all_numbers = odd_numbers + even_numbers
print(all_numbers)

Just as in strings, Python supports forming new lists with a repeating sequence using the multiplication operator:

print([1,2,3] * 3)

x = object()
y = object()

# TODO: change this code
x_list = [x] * 10
y_list = [y] * 10
big_list = x_list + y_list

print("x_list contains %d objects" % len(x_list))
print("y_list contains %d objects" % len(y_list))
print("big_list contains %d objects" % len(big_list))

# testing code
if x_list.count(x) == 10 and y_list.count(y) == 10:
    print("Almost there...")
if big_list.count(x) == 10 and big_list.count(y) == 10:
    print("Great!")