Fibonacci Sequence Generator using Python

This blog post demonstrates how to generate a Fibonacci sequence in Python. Fibonacci sequence is a series of numbers wherein the numbers are the sum of its two preceding numbers, i.e.,

It interests mathematicians as it appears in nature, e.g., in flower petals, galaxies, hurricanes, etc. It is named through the claimed discovery of famous Italian mathematician, Leonardo Fibonacci.

Now, let's generate a Fibonacci sequence using Python!

The following line of codes lets the user input a range. If the inputted range is not a positive integer, it lets the user try to input again.

try:
    Range = int(input("Enter a range: 1 to "))
    
except ValueError:
    print("\nInvalid input! Please input a positive integer only.")
    Range = int(input("Enter a range: 1 to "))

Next, the program defines a function that performs the operations to generate the sequence. It defines variables 'previous_number' and 'current_number', and initiates its values to 0 and 1, respectively. After that, it creates a list where the succeeding numbers to append appears. Then, it runs in a loop up until the current value does not exceed the range inputted by the user. Followingly, it adds up the previous number and the current number to produce a new number to append in the sequence. It also creates a condition that determines whether the current number is still in range. Then, it returns the list of the Fibonacci sequence generated.

def fibonacci(Range):                                    
    previous_number, current_number = 0, 1               
    
    fibonacci=[1,]
    
    while current_number < Range:
        
        previous_number += current_number
        current_number += previous_number
        
        fibonacci.append(previous_number)
        
        if current_number < Range:
            fibonacci.append(current_number)
        else:
            break
        
    return fibonacci

Lastly, the program calls the created function that executes to generate the sequence, and display the result.

print("Sequence = " + str(fibonacci(Range)))

That is all! We have generated a Fibonacci sequence using Python.