Python range() function – Explained with Code Examples

Asma Mushtaq

Python range() work returns the succession of the given number between the given reach.

range() is an implicit capacity of Python. It is utilized when a client needs to play out an activity on a particular number of occasions. range() in Python(3.x) is only a renamed adaptation of a capacity called xrange in Python(2.x). The reach() work is utilized to produce a succession of numbers.

Python range() work for the circle is generally utilized henceforth, information on same is the key angle when managing any sort of Python code. The most widely recognized utilization of reach() work in Python is to emphasize arrangement type (Python range() List, string, and so forth ) with for and keeping in mind that circle.

Python range language structure

Python range() Basics

In straightforward terms, range() permits the client to produce a progression of numbers inside a given reach. Contingent upon the number of contentions the client is passing to the capacity, the client can choose where that series of numbers will start and end just like the way in which enormous the distinction will be between one number and the next. range() takes basically three contentions.

  • start: number beginning from which the arrangement of whole numbers is to be returned
  • stop: number before which the grouping of whole numbers is to be returned. The scope of numbers ends at stop – 1.
  • step: number worth which decides the augmentation between every whole number in the succession
    Illustration of Python range() strategies

Example 1: Demonstration of Python range()

# Python Program to
# show range() basics
# printing a number
for i in range(10):
    print(i, end=" ")
print()
# using range for iteration
l = [10, 20, 30, 40]
for i in range(len(l)):
    print(l[i], end=" ")
print()
# performing sum of natural
# number
sum = 0
for i in range(1, 11):
    sum = sum + i
print("Sum of first 10 natural number :", sum)

Output :

0 1 2 3 4 5 6 7 8 9 
10 20 30 40 
Sum of first 10 natural number : 55

There are three ways you can call range() :

  • range(stop) takes one argument.
  • range(start, stop) takes two arguments.
  • range(start, stop, step) takes three arguments.

range(stop)

When user call range() with one argument, user will get a series of numbers that starts at 0 and includes every whole number up to, but not including, the number that user have provided as the stop. For Example –

Example 2:  Demonstration of Python range(stop)

# Python program to
# print whole number
# using range()
# printing first 10
# whole number
for i in range(10):
    print(i, end=" ")
print()
# printing first 20
# whole number
for i in range(20):
    print(i, end=" ")

Output:

0 1 2 3 4 5 6 7 8 9 
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

range(start, stop)

When user call range() with two arguments, user get to decide not only where the series of numbers stops but also where it starts, so user don’t have to start at 0 all the time. User can use range() to generate a series of numbers from X to Y using a range(X, Y). For Example -arguments

Example 3:  Demonstration of Python range(start, stop)

# Python program to
# print natural number
# using range
# printing a natural
# number upto 20
for i in range(1, 20):
    print(i, end=" ")
print()
# printing a natural
# number from 5 t0 20
for i in range(5, 20):
    print(i, end=" ")

Output:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

range(start, stop, step)

When the user call range() with three arguments, the user can choose not only where the series of numbers will start and stop but also how big the difference will be between one number and the next. If the user doesn’t provide a step, then range() will automatically behave as if the step is 1.

Example 4:  Demonstration of Python range(start, stop, step)

# Python program to
# print all number
# divisible by 3 and 5
# using range to print number
# divisible by 3
for i in range(0, 30, 3):
    print(i, end=" ")
print()
# using range to print number
# divisible by 5
for i in range(0, 50, 5):
    print(i, end=" ")

Output :

0 3 6 9 12 15 18 21 24 27 0 5 10 15 20 25 30 35 40 45

Example 5: Incrementing with the range using positive step 

If a user wants to increment, then the user needs steps to be a positive number. For example:

# Python program to
# increment with
# range()
# incremented by 2
for i in range(2, 25, 2):
    print(i, end=" ")
print()
# incremented by 4
for i in range(0, 30, 4):
    print(i, end=" ")
print()
# incremented by 3
for i in range(15, 25, 3):
    print(i, end=" ")

Output : 

2 4 6 8 10 12 14 16 18 20 22 24 
0 4 8 12 16 20 24 28 
15 18 21 24

Example 6: Python range() backwords

If a user wants to decrement, then the user needs steps to be a negative number. For example:

# Python program to
# decrement with
# range()
# incremented by -2
for i in range(25, 2, -2):
    print(i, end=" ")
print()
# incremented by -4
for i in range(30, 1, -4):
    print(i, end=" ")
print()
# incremented by -3
for i in range(25, -6, -3):
    print(i, end=" ")

Output :

25 23 21 19 17 15 13 11 9 7 5 3 
30 26 22 18 14 10 6 2 
25 22 19 16 13 10 7 4 1 -2 -5

Example 7: Python range() float

Python range() function doesn’t support the float numbers. i.e. user cannot use floating-point or non-integer number in any of its argument. Users can use only integer numbers. For example

# Python program to
# show using float
# number in range()
# using a float number
for i in range(3.3):
    print(i)
# using a float number
for i in range(5.5):
    print(i)

Output :

for i in range(3.3):
TypeError: 'float' object cannot be interpreted as an integer

Example 8: Concatenation of two range() functions

The result from two range() functions can be concatenated by using the chain() method of itertools module. The chain() method is used to print all the values in iterable targets one after another mentioned in its arguments.

# Python program to concatenate
# the result of two range functions
from itertools import chain
# Using chain method
print("Concatenating the result")
res = chain(range(5), range(10, 20, 2))
for i in res:
    print(i, end=" ")

Output:

Concatenating the result
0 1 2 3 4 10 12 14 16 18

Example 9: Accessing range() with index value

A sequence of numbers is returned by the range() function as its object that can be accessed by its index value. Both positive and negative indexing is supported by its object.

# Python program to demonstrate
# range function
ele = range(10)[0]
print("First element:", ele)
ele = range(10)[-1]
print("\nLast element:", ele)
ele = range(10)[4]
print("\nFifth element:", ele)

Output:

First element: 0

Last element: 9

Fifth element: 4

Points to remember about Python range() function :

  • range() function only works with the integers i.e. whole numbers.
  • All arguments must be integers. Users can not pass a string or float number or any other type in a start, stop and step argument of a range().
  • All three arguments can be positive or negative.
  • The step value must not be zero. If a step is zero python raises a ValueError exception.
  • range() is a type in Python
  • Users can access items in a range() by index, just as users do with a list:

Also Read: Difference between Worms and Trojan Horse

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