How to produce a fibonacci serie in Python?

What is Fibonacci Series? - It is a series of numbers formed by the sum of the two preceding numbers in the series.

 0,1,1,2,3,5

• The 1 is found by sum the two numbers before it (0+1)

• The 2 is found by sum the two numbers before it (1+1)

• The 3 is found by sum the two numbers before it (2+1)

• The 5 is found by sum the two numbers before it (2+3)

It is done until the number of terms you want or requested by the user.

Example:

length = int(input("Enter length: "))
#first element of series
first_element = 0  
#second element of series                                      
second_element=1                                       
if length<=0:
    print("The requested series is",first_element)
else:
    print(first_element,second_element,end=" ")
    for x in range(2,length):
        next=first_element+second_element                           
        print(next,end=" ")
        first_element = second_element
        second_element = next

Output - Using the number 8 as input:

0 1 1 2 3 5 8 13

Using a negative number the requested series is 0.

References

What is Fibonacci Series?

Fibonacci series explanation