9.4) Range

The function range() can come in handy when looping over the indexes of a list.

It creates a list containing a progression of integers. Here’s how you use it:

<list>= range(<start>, <end>, <step>)

The default start value is 0, and the default step is 1, but the end value does not have a default so it must be defined as an argument. The list will include the start value, but not the end value. start, end and step should be integers.

For example:

>>> range(5)      # uses the default start and step values, sets the end value to 5
[0, 1, 2, 3, 4]
>>> range(2,5)    # uses the default step value
[2,3,4]
>>> range(0,10,2) # manually sets the start, end and step values
[0,2,4,6,8])

• Create a list of all the integers starting at -5 and going up to (and including) 5
• Create the same list, but in the reverse order, from 5 to -5