## Introduction

Before we begin talking about the basics of Python `range()`

function, let's briefly understand – **What is Python range() function?**

Python `range()`

function is a built-in function used to generate a sequence of numbers. It is widely used in loops and iterations. The `range()`

function takes up to three arguments: start, stop, and step. By specifying these arguments, you can create a range of numbers starting from the 'start' value, up to but not including the 'stop' value, with an increment of 'step'.

This versatile function is commonly used to iterate over a specific range of values, making it essential for tasks like looping, list comprehension, and indexing. Understanding the `range()`

function is crucial for efficient programming in Python.

In this tutorial, we will explain the fundamentals of Python range() Function. We will also address a few FAQs on Python range() function.

## Advantages of Python range() function

**Simplicity:**Python's`range()`

function provides a straightforward way to generate number sequences without complicated logic.**Memory Efficiency:**It generates numbers on-the-fly, making it memory-efficient for large ranges.**Loop Control:**It simplifies loop control by specifying the start, stop, and step values.**Versatility:**It is used in various contexts like list comprehension and indexing.**Performance:**It improves performance by avoiding unnecessary memory allocation and iteration overheads.

## Python **range()**

syntax

**range()**

There are several variations of the `range`

constructor:

```
range(stop)
range(start, stop[, step])
```

The `range`

constructor accepts only integer arguments. The use of floating numbers and other types is prohibited.

One mandatory and two optional arguments are accepted by `range`

. It generates the numbers on demand and returns a range object that represents the provided range.

## Python **range(stop)**

**range(stop)**

`range`

returns a sequence of numbers, incremented by `1`

, starting from `0`

till `stop - 1`

, when only one argument is specified.

Here is an example of the range type in use:

```
for i in range(5):
print(i)
```

The generated sequence of numbers begins with `0`

and ends with `4`

(5-1):

```
Output
0
1
2
3
4
```

`range`

returns an empty sequence if the argument is `0`

or a negative integer:

```
print(list(range(-5)))
```

We are transforming the range object to a list because the range performs a slow evaluation of the integer sequence. An empty list appears as an output:

```
Output
[]
```

When two arguments are given, the `range`

returns a sequence of numbers, each one increased by `1`

, ranging from `start`

to `stop – 1`

.

An example is shown below:

```
for i in range(3, 5):
print(i)
```

```
Output
3
4
```

The `stop`

argument must be greater than the `start`

argument. The sequence is empty otherwise:

```
print(list(range(5, 3)))
```

```
Output
[]
```

Positive, negative, and `0`

digits can be used as arguments:

```
print(list(range(-5, -3)))
```

```
Output
[-5, -4]
```

```
print(list(range(-3, 0)))
```

```
Output
[-3, -2, -1]
```

## Python **range(start, stop, step)**

**range(start, stop, step)**

`range`

returns a series of numbers that are incremented or decremented by `step`

, starting from `start`

to `stop - 1`

, when three arguments are provided.

If `step`

is positive, `range`

returns an incrementing sequence:

```
for i in range(0, 26, 5):
print(i)
```

```
Output
0
5
10
15
20
25
```

The `stop`

argument must be greater than the `start`

argument while incrementing. The sequence is empty if not.

`range`

returns a sequence that decrements if `step`

is negative:

```
for i in range(20, 4, -5):
print(i)
```

```
Output
20
15
10
5
```

The `stop`

argument must be lesser than the `start`

argument while decrementing. The sequence is empty if not.

A ValueError exception is raised if `step`

is `0`

:

```
Output
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ValueError: range() arg 3 must not be zero
```

## FAQs About Python `range()`

Function

#### What is the default value for the start argument?

The default value for the start argument is `0`

.

#### Can the `range()`

function generate a sequence in reverse?

Yes, by providing a negative step value, the `range()`

function can generate numbers in reverse order.

#### How can I use the `range()`

function in a loop?

You can use the `range()`

function as an iterator in a for loop to iterate over a specific range of values.

#### Can I use floating-point values with the `range()`

function?

No, the `range()`

function only accepts integers as arguments.

#### Is the stop value included in the generated sequence?

No, the stop value is not included. The sequence generated by the `range()`

function stops one step before the stop value.

#### Can I create an empty sequence using the `range()`

function?

No, the `range()`

function requires at least one argument to generate a sequence.

#### How can I convert the `range()`

function output into a list?

You can use the `list()`

function to convert the output of the `range()`

function into a list.

## Conclusion

We hope this tutorial, helped you understand the fundamentals of Python range() Function.

If you have any queries, please leave a comment below, and we’ll be happy to respond to them.