Specifying the increment in for-loops in Python

Let us see how to control the increment in for-loops in Python. We can do this by using the range() function.

range() function

range() allows the user to generate a series of numbers within a given range. Depending on how many arguments the user is passing to the function, the user can decide where that series of numbers will begin and end as well as how big the difference will be between one number and the next.

Syntax: range(start, stop, step)

Parameters:

• start: integer starting from which the sequence of integers is to be returned
• stop: integer before which the sequence of integers is to be returned
• step: integer value which determines the increment between each integer in the sequence

Returns: a list

Example 1: Incrementing the iterator by 1.

Python3

for i in range(5):
  print(i)

Output:

0
1
2
3
4

Example 2: Incrementing the iterator by an integer value n.

Python3

# increment value
n = 3

for i in range(0, 10, n):
  print(i)

Output:

0
3
6
9

Example 3: Decrementing the iterator by an integer value -n.

Python3

# decrement value
n = -3

for i in range(10, 0, n):
  print(i)

Output:

10
7
4
1

Example 4: Incrementing the iterator by exponential values of n. We will be using list comprehension.

Python3

# exponential value
n = 2

for i in ([n**x for x in range(5)]):
  print(i)

Output:

1
2
4
8
16

Time complexity: O(n), where n is the number of iterations.
Auxiliary space: O(1), as only a constant amount of extra space is used to store the value of “i” in each iteration.