random() Function in Python

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Python Course for Beginners With Certification: Mastering the Essentials
Python Course for Beginners With Certification: Mastering the Essentials
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Python Course for Beginners With Certification: Mastering the Essentials
Python Course for Beginners With Certification: Mastering the Essentials
by Rahul Janghu
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4.90
Start Learning
Topics Covered

In the world of programming, the ability to generate random numbers is essential for various applications, from simulations and games to security and data analysis.

With its vast standard library, Python offers a robust solution through the random module, which is a cornerstone for the random function in Python. It has an in-built random library used to generate random numbers with the help of various in-built functions, making the random function in Python a versatile tool for developers.

This introduction guides how to use random function in Python, illustrating its application in generating OTPs, lottery tickets, etc., and showcasing the utility and flexibility of the random functions in Python's ecosystem.

Python Random random() Syntax

The syntax of the random() function is straightforward and easy to use:

Python Random random() Parameters

The Python random module's random() function is a key example of the random function in Python, remarkably straightforward primarily because it does not require any parameters to operate.

  • None: The random() function, a fundamental random function in Python, is designed to be parameter-free. It automatically generates a random float number between 0.0 and 1.0 when called.

This absence of parameters ensures that random() can be seamlessly integrated into various contexts without the need for any customization, highlighting the versatility and ease of use of the random function in Python. The function's simplicity ensures that it can serve as a foundational element for more operations or algorithms requiring randomization, making it an essential tool in Python's random module.

Python Random random() Returns

The random() function from Python's random module is elegantly simple in its usage and output. When called, it returns a single value with the following characteristics:

  • Type: The function returns a float.
  • Range: The value is always between 0.0 and 1.0, including 0.0 but not including 1.0.

Random Method in Python Examples

1. Generating a Floating Random Number Between 0 and 1

The random() function, a key example of the random function in Python, is the most straightforward method in the random module, used to generate a floating-point number between 0.0 and 1.0. The number returned is inclusive of 0.0 and exclusive of 1.0.

Code:

Output:

Explanation: This code snippet imports the random module and uses the random() function to generate a floating-point number between 0.0 and 1.0. Each execution of this line will produce a different pseudo-random number within this range.

2. Random in Python Generates a Different Number Every Time the Program is Run

One of the feature of the random module, showcasing the versatility of the random function in Python, is its ability to produce a different number each time your program is executed. This behavior is due to the underlying pseudo-random number generator (PRNG), which uses an initial seed based on the system time to generate random sequences.

Code:

Output:

Explanation: This example demonstrates that each call to random.random() generates a new pseudo-random floating-point number between 0.0 and 1.0. Running the entire program multiple times will also result in different sequences of numbers, illustrating the pseudo-randomness and the non-repetitive nature of the output.

3. List of Random Numbers

Often, applications require not just a single random number but a list of random numbers. The random module offers several ways to generate lists of random numbers. For instance, you can use a list comprehension combined with the random() function to generate a list of random floats.

Code:

Output:

Explanation: This code uses a list comprehension to generate a list of 5 random floating-point numbers, each between 0.0 and 1.0. By iterating with a range of 5, it calls random.random() five times, storing each new random number in the list.

4. Random seed() Method

The seed() method is crucial for controlling the randomness in Python. By setting a seed value, you initialize the PRNG to a known state, making the sequence of random numbers predictable and reproducible. This is especially useful in debugging or ensuring that your program yields the same results on each run for testing or demonstration purposes.

Code:

Output:

Explanation: The seed() method is used to initialize the random number generator in Python. The pseudo-random number generator produces the same sequence of numbers starting from that seed by setting the seed to a specific value (in this case, 10). This is why the two calls to random.random(), with the seed reset to the same value beforehand, produce an identical number. Seeding is helpful in creating reproducible results during testing or simulation.

Conclusion

  1. First, we get familiar with a random number and how it gets generated in Python.
  2. Then, we use different functions of the built-in Python module to generate random numbers.
  3. After that, we generate a single random number using the random function.
  4. Then, we create a random number within a given range of numbers.
  5. Afterwards, we create a list of different random numbers.

See Also