input: Write a function to modify the given Python code such that it raises an exception if the input value is not an integer. The function should keep the original functionality of returning the square root of the input when the input is an integer.
  
  def square_root(x):
      if not isinstance(x, int):
          raise TypeError('Input must be an integer')
      return x**0.5
  
  assert square_root(4)==2.0
  assert square_root(9)==3.0
  assert square_root(0)==0.0
  try:
      square_root(4.0)
  except TypeError:
      pass
  else:
      assert False
  try:
      square_root('4')
  except TypeError:
      pass
  else:
      assert False
output: def square_root(x):
      if not isinstance(x, int):
          raise TypeError('Input must be an integer')
      return x**0.5