input: Write a function to generate a Fibonacci sequence of the first n numbers. If n is 1, return the first Fibonacci number. If n is greater than 1, return the Fibonacci sequence up to the nth number.
  
  def show_fibo(n):
      if n==1:
          return [0]
      elif n==2:
          return [0, 1]
      else:
          fib_sequence = [0, 1]
          for i in range(2, n):
              fib_sequence.append(fib_sequence[-1] + fib_sequence[-2])
          return fib_sequence
  
  assert show_fibo(1)==[0]
  assert show_fibo(2)==[0, 1]
  assert show_fibo(5)==[0, 1, 1, 2, 3]
  assert show_fibo(7)==[0, 1, 1, 2, 3, 5, 8]
  assert show_fibo(10)==[0, 1, 1, 2, 3, 5, 8, 13, 21, 34]
output: def show_fibo(n):
      if n==1:
          return [0]
      elif n==2:
          return [0, 1]
      else:
          fib_sequence = [0, 1]
          for i in range(2, n):
              fib_sequence.append(fib_sequence[-1] + fib_sequence[-2])
          return fib_sequence