How to Use the Python range() Function

09/07/2021

Contents

In this article, you will learn how to use the Python range() function.

Python range() Function

The range() function in Python generates a sequence of numbers, starting from 0 by default, and increments by 1 (by default), and stops before a specified number.

The numbers generated by range() are used as indices for iterating over a sequence, such as lists, tuples, and strings.

The function is an efficient way to generate a sequence of numbers as it generates the numbers on-the-fly, rather than storing them in memory as a list.

The basic syntax for range() is as follows:

range(stop)

stop is the upper bound of the sequence, and is not included in the sequence.

This generates a sequence of numbers from 0 to stop-1.

The function works with any integer value, including negative numbers.

The following is an example of how to use the range() function to generate a sequence of numbers from 0 to 9:

for i in range(10):
  print(i)

You can also specify the start and step of the sequence by using the following syntax:

range(start, stop, step)

start is the first number in the sequence, defaulting to 0 if not specified. step is the difference between each number in the sequence, defaulting to 1 if not specified.

The function can also be used to generate sequences of numbers with a step of -1, allowing for generation of decreasing sequences.

For example, to generate a sequence of even numbers from 0 to 10, you can use the following code:

for i in range(0, 11, 2):
  print(i)

Note that the range() function generates a sequence of numbers, and does not return a list. To generate a list, you need to use the list() function, like so:

my_list = list(range(10))
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