Python |Generate Random Integer Number within a range using random.randrange() and randint()

In this article, we will learn how to implement Python random.randrange() and random.randint(). These functions are used to generate a random integer within a range.

How to use random.randint()

Syntax:

random.randint(start, stop)

Examples:

While generating random integer the randint(start, stop) includes both start and stop numbers. It will generate a random number within the inclusive range.

import random

num1 = random.randint(0, 9)
print("Random integer from 0 to 9: ", num1)

num2 = random.randint(10, 100)
print("Random integer from 10 to 100: ", num2)

Output:

How to use random.randrange()

Syntax:

random.randrange(start, stop, step)

This function returns a randomly selected integer by taking three parameters i.e., range(start, stop, step). Start and Step are the optional parameters.

Examples:

import random

# Random number between 0 and 39
num1 = random.randrange(40)
print("Random integer: ", num1)

# Random number between 20 and 39
num2 = random.randrange(20, 40)
print("Random integer: ", num2)

#generating Random number between 25 and 249 and is also divisible by 5
num3 = random.randrange(25, 250, 5)
print("Random integer: ", num3)

Output:

Generate a random integer number multiple of n

In the below example, we will generate a random number between x and y, which is a multiple of 3.

Example:

import random
num = random.randrange(3, 300, 3)
print("Generating random number with multiple of 3 is", num)

Output:

Generating random number with multiple of 3 is 150

Generate a random negative integer

Let’s see look at how to generate a random negative integer between -60 to -6.

Example:

import random

singedInt = random.randrange(-50, -1)
print("Random negative integer between -50 to -1")
print(singedInt)

Output:

Generate a list of random integer numbers

Here, we will see how to generate multiple random numbers. In this case, we can create a list with random integers using randint() or randrange(). In this example, we will see how to create a list of 20 random integers.

Example:

import random

randomList = []
# Set a length of the list to 20
for i in range(0, 20):
  # any random numbers from 0 to 1000
randomList.append(random.randint(0, 1000))

print("Printing list of 20 random numbers")
print(randomList)

Output:

Create a list of random numbers without duplicates

In the above-mentioned example, there is a chance to get a duplicate random number in a list. Hence to avoid duplication we can use random.sample() to create a list of unique random numbers.

Example:

import random
#within a range generating unique random numbers
randomList = random.sample(range(0, 1000), 10)
print(randomList)

Output: