Numeric types in 5 minutes

There are 3 distinct numeric types: integers, floating point numbers, and complex numbers.

Integers

An integer is a whole number without decimal places. For instance 18 is an integer but 18.1 is not. The name for the integer data type is int and you can check the type of a value using the type function.

>>> type(18)
<class 'int'>

You can use the int() function to create integers. The following is the same as x = 18.

x = int(18)
# x is now 18

You can also use int() to convert from string values to integer values:

x = int("18")
# x is now 18

For readability purposes, you can use underscores (_) to group digits:

x = 1_000_000_000
# x is 1000000000

An integer has no theoretical maximum limit in python, so, you can have a integer as big as this one:

x = 1_000_000_000_000_000_000
# 1 quintillion

In practice, the biggest value you can represent in Python will depend on your computer's memory.

Floating pointing numbers

An floating pointing number (or float) is a number with decimal places. For instance 18 is not a float but 18.1 is. The name for the float data type is float and you can check the type of a value using the type function.

>>> type(18.1)
<class 'float'>

You can use the float() function to create integers. The following is the same as x = 18.18.

x = float(18.18)
# x is now 18.18

You can also use float() to convert from string values to integer values:

x = float("18.18")
# x is now 18.18

As well as an integer, a float has no theoretical maximum limit in python, so, you can have a float like this one:

x = 1_000_000_000_000_000.12
# 1 quintillion plus some decimal places

However, if you need to preserve the decimal places without rouding or losing precision, you should use the decimal module.

Operations

Integers and floats support the following operations:

Operation	x	y	result	description
x + y	10	3	13	sum of x and y
x - y	10	3	10	difference of x and y
x * y	10	3	30	product of x and y
x / y	10	3	3.333...	quotient of x and y
x // y	10	3	3	floored quotient of x and y (integer division of x and y)
x % y	10	3	2	remainder of x divided by y
-x	10		-10	x negated
+x	10		10	x unchanged
abs(x)	-10		10	the absolute (magnitude) value of x
pow(x, y)	10	3	1000	x to the power of y
x ** y	10	3	1000	x to the power of y