input: Write a function to modify the given Python code to raise an exception if the input value is not an integer. The original function calculates the square root of the input. If the input value is not an integer, raise a TypeError with the message 'Input must be 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
  assert square_root("4")
output: def square_root(x):
      if not isinstance(x, int):
          raise TypeError('Input must be an integer')
      return x**0.5