Python - Random Module

Python provides an inbuilt module named random.

This module defines several functions to generate random numbers.

Using these functions, we can generate different random values whenever a program is executed.

The random module is useful whenever unpredictable values are required.

We can use these functions while:

• Developing games.
• Cryptography.
• Generating random numbers on the fly for authentication.

In this section, we will learn the following functions:

1. random()
2. uniform()

The random() function always generates a floating-point value between 0 and 1.

The generated value is always greater than 0 and less than 1.

The random() function generates a floating-point value every time it is called.

Each generated value lies between 0 and 1.

The value is never exactly 0 or 1.

Every execution of the program produces different values.

Note: Every execution produces different values.

The uniform(a, b) function returns a random floating-point number between the specified range.

Unlike random(), we can specify both the starting value and ending value.

The generated value may be any floating-point number between 1 and 10.

Every execution produces different values because the numbers are generated randomly.

This function is useful whenever random decimal values are required within a specified range.

• Game development.
• OTP generation.
• Password generation.
• Lottery systems.
• Simulation software.
• Testing applications using random data.
• Cryptography-related programs.

1. What is the purpose of the random module?
2. What type of value is returned by random()?
3. What is the range of the random() function?
4. What is the difference between random() and uniform()?
5. Which function allows us to specify the range?
6. Why do random numbers change every execution?
7. Where is the random module commonly used?
8. Can uniform() generate decimal values?

The random module also provides functions to generate random integer values.

Unlike random() and uniform(), these functions generate whole numbers (integers).

In this section, we will learn:

1. randint()
2. randrange()

The randint(a, b) function returns a random integer between a and b.

Both the starting value and ending value are included in the generated range.

The randint(1, 10) function generates a random integer between 1 and 10.

Both 1 and 10 are included in the possible output.

Each execution of the program produces different random numbers.

• The generated value is always an integer.
• Both the beginning and ending values are included.
• Every execution produces different random values.

The randrange() function returns a random integer from the specified range.

Its behavior is similar to Python's built-in range() function.

It is useful when random values are required from a sequence.

The statement randrange(10) generates a random integer from 0 to 9.

The ending value 10 is not included.

The statement randrange(1, 11) generates a random integer between 1 and 10.

The ending value 11 is excluded.

The third parameter specifies the step value.

In this example, only odd numbers are generated because the step size is 2.

Possible values are:

1, 3, 5, 7, 9, 11, 13, 15, 17, 19

• Dice simulation.
• Lottery number generation.
• Card games.
• Quiz applications.
• OTP generation.
• Random test case generation.
• Gaming applications.

1. What is the difference between randint() and randrange()?
2. Does randint() include the ending value?
3. Does randrange() include the ending value?
4. Which function supports a step value?
5. What is the output range of randrange(10)?
6. How do you generate only odd numbers using the random module?
7. Which function behaves like Python's range()?
8. Name two functions used to generate random integers.

The random module also provides functions that work with sequences such as lists and tuples.

These functions do not always generate random numbers. Instead, they can select random elements from a sequence.

In this section, we will learn the choice() function.

The choice() function does not return a random number.

It returns a random object from the given list or tuple.

Every time the function is executed, it may return a different element from the sequence.

The list contains five names.

Each time choice(list) is called, Python randomly selects one element from the list.

The selected element is returned and displayed.

The same element may appear multiple times because every selection is independent.

• choice() works with sequences such as lists and tuples.
• It returns only one element at a time.
• The returned element is selected randomly.
• The same value can be selected multiple times.
• It does not generate a random number.

• Selecting a random winner from a list.
• Displaying random motivational quotes.
• Choosing random quiz questions.
• Selecting random names in classrooms.
• Random card selection in games.
• Random recommendation systems.

1. What is the purpose of the choice() function?
2. Does choice() return a random number?
3. Which data structures are supported by choice()?
4. Can the same element be selected multiple times?
5. What is the difference between choice() and randint()?
6. Name five important functions of the random module.
7. Which function returns a random object from a sequence?
8. Where is the choice() function commonly used?

• Easy to generate random values.
• Provides both integer and floating-point random numbers.
• Can randomly select elements from lists and tuples.
• Useful for simulations and testing.
• Reduces the need to implement custom random number algorithms.
• Built into Python, so no external installation is required.

• Game development.
• Lottery systems.
• Online quiz applications.
• Password and OTP generation.
• Authentication systems.
• Simulation software.
• Random testing and test data generation.
• Artificial Intelligence and Machine Learning experiments.

1. What is the purpose of the random module?
2. Which function returns a floating-point number between 0 and 1?
3. What is the difference between random() and uniform()?
4. What is the difference between randint() and randrange()?
5. Which function returns a random object from a list?
6. Can choice() return duplicate values?
7. Which random function supports a step value?
8. Which functions generate floating-point numbers?
9. Which functions generate integers?
10. List five functions available in the random module.
11. Where is the random module commonly used?
12. Is the random module built into Python?