Python

Generators

def fibonacci():
  # yield 0 and 1 directly
  first = 0
  yield first
  second = 1
  yield second

  while True: # Loop infintely
    third = first + second # <-- Calculate the next number in the series
    yield third # <-- Yield the next number in the series
    first = second
    second = third

fib_gen = fibonacci()
for _ in range(10): # Loops for 10 iterations
  print(next(fib_gen), end="\t") # <-- Can generate the next number infintely