input: Write a python function to generate Fibonacci sequence of given length.
  assert generateFibo(5) == [0, 1, 1, 2, 3]
  assert generateFibo(7) == [0, 1, 1, 2, 3, 5, 8]
  assert generateFibo(10) == [0, 1, 1, 2, 3, 5, 8, 13, 21, 34]
output: def generateFibo(n):
      if n <= 0:
          return []
      fibo_sequence = [0, 1]
      while len(fibo_sequence) < n:
          fibo_sequence.append(fibo_sequence[-1] + fibo_sequence[-2])
      return fibo_sequence[:n]