infinite Fibonacci generator in python with yield error?

Question

def fib_gen():
    a, b = 0, 1
    while True:
        yield a
        a, b = b, a + b

print(next(fib_gen())) 
print(next(fib_gen())) 
print(next(fib_gen())) 
print(next(fib_gen()))

Output: 0 
        0 
        0 
        0

I am trying to create an infinite Fibonacci generator in python. Please help ... Where am I doing wrong ?

Possible duplicate of [Python Fibonacci Generator](https://stackoverflow.com/questions/3953749/python-fibonacci-generator) — , Jul 01 '18 at 05:37
Thanks but No @insaner.. In infinite series I get this code from web everywhere.. but it is resetting the value of a every-time it is called. — Sameer Pradhan, Jul 01 '18 at 05:39

score 6 · Accepted Answer · answered Jul 01 '18 at 05:39

6

Each call to fib_gen() creates a new generator that is in initial state. Try assigning the return value of fib_gen() to a variable and calling next() on that same variable.

answered Jul 01 '18 at 05:39

Tugrul Ates

9,451
2
33
59

score 5 · Answer 2 · answered Jul 01 '18 at 05:43

You first need to create a generator object:

def fib_gen():
    a, b = 0, 1
    while True:
        yield a
        a, b = b, a + b


generator = fib_gen()

print(next(generator))
print(next(generator))
print(next(generator))
print(next(generator))

The output is:

infinite Fibonacci generator in python with yield error?

2 Answers2