Often, we want to create a list of consecutive numbers in our programs. For example, suppose we want a list containing the numbers 0 through 9:

my_list = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

Typing out all of those numbers takes time and the more numbers we type, the more likely it is that we have a typo that can cause an error.

Python gives us an easy way of creating these types of lists using a built-in function called range().

The function range() takes a single input, and generates numbers starting at 0 and ending at the number before the input.

So, if we want the numbers from 0 through 9, we use range(10) because 10 is 1 greater than 9:

my_range = range(10)
print(my_range)

Would output:

range(0, 10)

Notice something different? The range() function is unique in that it creates a range object. It is not a typical list like the ones we have been working with.

In order to use this object as a list, we have to first convert it using another built-in function called list().

The list() function takes in a single input for the object you want to convert.

We use the list() function on our range object like this:

print(list(my_range))

Would output:

[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

Let’s try out using range()!