input: Write a function to generate the Fibonacci series up to n numbers where n is a user input. The function should print the series if n is greater than 0, otherwise it should print nothing.
  assert fibonacci_series(10) == None
  assert fibonacci_series(0) == None
  assert fibonacci_series(5) == None
output: def fibonacci_series(n):
      if n > 0:
          a, b = 0, 1
          for _ in range(n):
              print(a, end=' ')
              a, b = b, a + b
          print()