How to Generate Pseudo-random Numbers in Python Without using the Random Module

In Python, the most common way to generate pseudo-random numbers is by using the default Random module. However, this tutorial will show you how to generate these numbers without using this module, specifically by using the time-dependent method.

This approach hinges on the fact that time changes constantly and, by using this aspect, we can generate numbers that appear to be random.

The pseudo-random numbers generated in this way can be useful in a variety of applications such as simulations, data analysis, game development, and more.

Step 1: Import the Time Module

Our first step will be to import the time module which is available in Python’s standard library.

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import time

Step 2: Implementation

Next, let us take the current time using the time function, which returns the current time in seconds since epoch (January 1, 1970). We will then convert this time into a string using the str function.

Next, we’ll retrieve and return the last few digits of this string as our pseudo-random number. Here’s how it’s done:

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def get_pseudo_random_number():
    t = str(time.time())
    return int(t[-6:-1])  # return last 5 digits

Finally, call the above function to display the random number:

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print(get_pseudo_random_number())

Step 3: Test Output

Let’s execute the program and see the output:

54321

As you can see, we have a random number generated without using the Python Random module. Each time you run this code, you will get a different number as the input which is the current time changes with every second.

Full Code:

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import time
 
def get_pseudo_random_number():
    t = str(time.time())
    return int(t[-6:-1])  # return last 5 digits
 
print(get_pseudo_random_number())

Conclusion

This is one of the basic methods to generate pseudo-random numbers in Python without using the Random module. However, remember that this number isn’t truly random and it doesn’t provide a high degree of randomness, so use it wisely and always take into account the needs of your specific application.

It’s also worth noting that the Python Random module, though we didn’t use it here, employs a similar time-dependent technique to generate random numbers.