## How to Use the Python range Function

In this tutorial, we'll learn what does **range** function do in Python and how to use it. The **Python range** is built-in function that returns a sequence of numbers, starting from a given number up to the specified number. This function is generally used to iterate over with a **For loop**.

### Python range Function Syntax

The syntax of the **range** function is as follows:

range(stop)

or:

range(start,stop[,step])

- The
**start**argument is a starting integer number of the sequence. It defaults to 0, if not specified. - The
**stop**argument is a integer number that**range**function generates up to, but not including this number. - The
**step**argument is a difference between each number in the sequence. It defaults to 1, if not specified.

For the first syntax, **range**() returns a sequence of numbers up to, but not including the **stop** number. For example, **range**(10) returns a sequence of numbers, starting from 0 to 9.

For the second syntax, the **step** argument is optional, and it defaults to 1, if not specified.

### Examples

Now, let's take a look at the following example:

range(2,10)

Here, the **step** argument is omitted, and defaults to 1. The range(2,10) generates a sequence of numbers as follows:

= 2, 2 + 1, 2 + 2, 2 + 3, 2 + 4, 2 + 5, 2 + 6, 2 + 7

=2, 3, 4, 5, 6, 7, 8, 9

Next, let's take a look at another example below:

range(2,10,2)

Here, the **step** argument is 2, so the **range** function generates a sequence of numbers as follows:

=2, 2 + 2, 2 + 4, 2 + 6

=2, 4, 6, 8

### Using the range() with a For Loop

In this section, I give you examples how to use the **range**() function with a **For loop**.

#### Example 1

The following code illustrates how to use the range() function with a **For loop**:

sum = 0;

for i in range(10):

sum += i

print("The total is ", sum)

This program calculates the sum of all numbers in the sequence generated by the range(10). The program sums a sequence of numbers as follows:

= 0 + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9

= 45

#### Example 2

The following illustrates how to use the **range**() function with a **For loop**:

for i in range(2, 10, 3):

print("The value of i is ", i)

The result is as follows:

The value of i is 2

The value of i is 5

The value of i is 8

In this tutorial, we've learned what does the **Python range**() function do and how to use it. The **range**() is a built-in function that generates a sequence of numbers and it's generally used to iterate over with **a For loop**.

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