The term *arithmetic progression*
refers to a sequence of numbers such that the difference
between any two successive elements is the same.
Examples: [1, 2, 3, 4, 5]; [10, 20, 30, 40]; [88, 77, 66,
55, 44, 33].

Python's built-in `range()`

function returns
a list containing an arithmetic progression. There are
three different ways to call this function.

To generate the sequence [0, 1, 2, ..., * n*-1], use the form

`range(``n`

)

.
>>> range(6) [0, 1, 2, 3, 4, 5] >>> range(2) [0, 1] >>> range(0) []

Note that the sequence will never include the value of
the argument

; it stops one value short.
`n`

To generate a sequence [* i*,

`i`

`i`

`n`

`range(``i`

, `n`

)

:
>>> range(5,11) [5, 6, 7, 8, 9, 10] >>> range(1,5) [1, 2, 3, 4]

To generate an arithmetic progression with a difference

between
successive values, use the three-argument form `d`

`range(`

. The resulting sequence will be [* i*,

`n`

`d`

`i`

`i`

`d`

`i`

`d`

`n`

.
>>> range ( 10, 100, 10 ) [10, 20, 30, 40, 50, 60, 70, 80, 90] >>> range ( 100, 0, -10 ) [100, 90, 80, 70, 60, 50, 40, 30, 20, 10] >>> range ( 8, -1, -1 ) [8, 7, 6, 5, 4, 3, 2, 1, 0]