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Python Programs - Looping Statements

Generate Fibonacci series up to n terms - Python Program

Example 1 :

# Fibonacci series up to n terms

n = int(input("Enter number of terms: "))

a, b = 0, 1
print("Fibonacci Series:", end=" ")

for _ in range(n):
    print(a, end=" ")
    a, b = b, a + b

 
OUTPUT  :
Enter number of terms: 5
Fibonacci Series: 0 1 1 2 3 
 

Explanation:

• Starts with 0, 1.
• Each term = sum of previous two terms.
• Complexity: O(n).

Example 2 : Advanced Program

def generate_fibonacci_series(n_terms):
    """
    Generates the Fibonacci series up to n_terms.

    Args:
        n_terms (int): The number of terms to generate in the Fibonacci series.

    Returns:
        list: A list containing the Fibonacci series up to n_terms.
    """
    if n_terms <= 0:
        return []
    elif n_terms == 1:
        return [0]
    else:
        fib_series = [0, 1]
        while len(fib_series) < n_terms:
            next_term = fib_series[-1] + fib_series[-2]
            fib_series.append(next_term)
        return fib_series

# Example usage:
num_terms = 10
fibonacci_result = generate_fibonacci_series(num_terms)

print(f"Fibonacci series up to {num_terms} terms:")
print(fibonacci_result)

 
OUTPUT  :
Fibonacci series up to 10 terms:
[0, 1, 1, 2, 3, 5, 8, 13, 21, 34]
 

Explanation:

generate_fibonacci_series(n_terms) function:

• This function takes an integer n_termsas input, representing the desired number of terms in the Fibonacci series.
• Base Cases:
  • If n_termsis less than or equal to 0, an empty list is returned, as no terms can be generated.
  • If n_termsis 1, a list containing only 0 is returned, as it's the first term of the series.
• Initialization:For n_terms greater than 1, a list fib_series is initialized with the first two terms: [0, 1].
• Iteration:A while loop continues as long as the length of fib_series is less than n_terms.
  • Inside the loop, next_termis calculated by adding the last two elements of fib_series (fib_series[-1] and fib_series[-2]).
  • The next_termis then appended to the fib_series
• Return Value:The function returns the fib_series list containing the generated Fibonacci numbers.