The range()Function

In Python, the range() function is used to generate a sequence of numbers. It returns an object that represents a sequence of numbers from a start value to an end value, with an optional step value. The range() function can be used in for loops, list comprehensions, or anywhere you need to iterate over a sequence of numbers.

The syntax for the range() function is as follows:

range(start, stop, step)

The start parameter specifies the starting value of the sequence (inclusive). If not provided, it defaults to 0. The stop parameter specifies the end value of the sequence (exclusive). The step parameter (optional) specifies the increment between each number in the sequence. If not provided, it defaults to 1.

Here are a few examples to illustrate the usage of the range() function:

Iterate over a sequence of numbers from 0 to 9:

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

Iterate over a sequence of numbers from 5 to 14 (exclusive) with a step of 2:

for num in range(5,15,2):
    print(num)

Generate a list of numbers from 1 to 5:

numbers = list(range(1,6))
print(numbers)

Try the above examples for yourself to see the outputs.

Note that in Python 3.x, the range() function returns a special range object that behaves like a sequence of numbers but doesn’t generate the entire sequence in memory. Instead, it generates the numbers on-the-fly as they are needed, which is more memory-efficient. If you need to create a list of numbers, you can convert the range object to a list using the list() function, as shown in the last example.