input: Write a function to find the smallest number in a given list of integers. The function should return the smallest number.
  
  def smallestNumber(nums):
      smallest = nums[0]
      for i in range(1, len(nums)):
          if nums[i] < smallest:
              smallest = nums[i]
      return smallest
  
  assert smallestNumber([4, 5, 6, 7, 8])==4
  assert smallestNumber([1, 2, 3, 4, 5])==1
  assert smallestNumber([9, 8, 7, 6, 5])==5
  assert smallestNumber([-1, -2, -3, -4, -5])==-5
  assert smallestNumber([0])==0
output: def smallestNumber(nums):
      smallest = nums[0]
      for i in range(1, len(nums)):
          if nums[i] < smallest:
              smallest = nums[i]
      return smallest