Random Module in Python

The `random` module in Python provides functions for generating random numbers. It is part of the standard library and is commonly used in various applications such as simulations, games, and cryptography. Let’s explore the `random` module in detail, including the `range()` function and different ways to generate random numbers.

Basic Random Number Generation:

1. `random()` Function:

– The `random()` function returns a random floating-point number in the range [0.0, 1.0).

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import random

random_number = random.random()
print(random_number)

2. `randrange()` Function:

– The `randrange()` function generates a random integer from the specified range.  

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import random

random_integer = random.randrange(1, 10) # Generates a random integer from 1 to 9
print(random_integer)

Range Functions:

1. `randint()` Function:

– The `randint(a, b)` function returns a random integer in the range [a, b].

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import random

random_integer = random.randint(1, 10) # Generates a random integer from 1 to 10
print(random_integer)

2. `uniform()` Function:

– The `uniform(a, b)` function returns a random floating-point number in the range [a, b).  

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import random

random_float = random.uniform(1.0, 5.0) # Generates a random float from 1.0 to 5.0
print(random_float)

3. `randint()` vs `randrange()` and `uniform()` vs `random()`:

– `randint(a, b)` is inclusive of both `a` and `b`. – `randrange(a, b)` is exclusive of `b`. – `uniform(a, b)` is used for generating floating-point numbers.  

Random Sequences:

1. `shuffle()` Function:

– The `shuffle(sequence)` function shuffles a sequence randomly (e.g., a list).  

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import random

my_list = [1, 2, 3, 4, 5]
random.shuffle(my_list)
print(my_list)

2. `sample()` Function:

– The `sample(sequence, k)` function returns a randomly selected sample of size `k` from a sequence.  

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import random

my_list = [1, 2, 3, 4, 5]
random_sample = random.sample(my_list, 3) # Selects 3 random elements from the list
print(random_sample)

 

Seed for Reproducibility:

– Setting a seed using `seed()` ensures reproducibility, meaning the same sequence of random numbers will be generated on different runs.  

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import random

random.seed(42) # Setting a seed
random_number = random.random()
print(random_number)

Conclusion:

The `random` module in Python provides a versatile set of functions for generating random numbers and sequences. Depending on your requirements, you can choose the appropriate function to generate integers, floating-point numbers, or shuffle sequences. Additionally, using `seed()` can be useful for reproducibility in certain scenarios.