Practical Programming, 2nd Edition

Looping Over a Range of Numbers

We can also loop over a range of values. This allows us to perform tasks a certain number of times and to do more sophisticated processing of lists and strings. To begin, we need to generate the range of numbers over which to iterate.

Generating Ranges of Numbers

Python’s built-in function range produces an object that will generate a sequence of integers. When passed a single argument, as in range(stop), the sequence starts at 0 and continues to the integer before stop:

>>> range(10)
range(0, 10)

This is the first time that you’ve seen Python’s range type. You can use a loop to access each number in the sequence one at a time:

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