The range() function is used to generate a sequence of numbers. It takes three arguments: start, stop, and step, and returns a sequence of numbers starting from start, up to but not including stop, in increments of step. Here are some examples:
To generate a sequence of numbers from 0 to 9:
for i in range(10):
print(i)
This will print the numbers 0 through 9.
To generate a sequence of even numbers from 0 to 8:
for i in range(0, 10, 2):
print(i)
This will print the even numbers 0, 2, 4, 6, and 8.
You can also convert the range() object into a list or tuple using the list() or tuple() constructor respectively.
In Python 2.x there is a similar function called xrange() that returns an object that generates the numbers on-the-fly instead of generating a full list at once, making it memory efficient for large ranges. However, it is not available in Python 3.x as the built-in range() function accomplishes the same.