Range function

The built-in function range() is used to iterate over a sequence of numbers.When working with range(), you can pass between 1 and 3 integer arguments to it:

• start states the integer value at which the sequence begins, if this is not included then start begins at 0
• stop is always required and is the integer that is counted up to but not included
• step sets how much to increase (or decrease in the case of negative numbers) the next iteration, if this is omitted then step defaults to 1.

range(stop):

for i in range(6):
   print(i)

In the program above, the stop argument is 6, so the code will iterate from 0-6 (exclusive of 6)

Output:

0
1
2
3
4
5

range(start, stop)

for i in range(20,25):
   print(i)

Here, the range goes from 20 (inclusive) to 25 (exclusive), so the output looks like this:

Output

20
21
22
23
24

range(start, stop, step): step with a positive value:

for i in range(0,15,3):
   print(i)

In this case, the for loop is set up so that the numbers from 0 to 15 print out, but at a step of 3, so that only every third number is printed, like so:

Output

0
3
6
9
12

range(start, stop, step): step with a negative value:

for i in range(100,50,-10):
   print(i)

Output

100
90
80
70
60