The range() Function

January 10, 2021

If you do need to iterate over a sequence of numbers, the built-in python function range() comes in handy. It generates arithmetic progressions:

>>> for i in range(5):
...     print(i)
...
0
1
2
3
4

range(5, 10)
   5, 6, 7, 8, 9

range(0, 10, 3)
   0, 3, 6, 9

range(-10, -100, -30)
  -10, -40, -70

>>> a = ['100', '200', '30000', '500000', '1000000']
>>> for i in range(len(a)):
...     print(i, a[i])
...
0 100
1 200
2 30000
3 500000
4 1000000

>>> sum(range(4))  # 0 + 1 + 2 + 3
6

>>> list(range(4))
[0, 1, 2, 3]