input: Write a python function to handle division by zero and return a specific message.
  assert safe_divide(5, 0) == 'Cannot divide by zero!'
  assert safe_divide(10, 2) == 5.0
  assert safe_divide(7, 1) == 7.0
output: def safe_divide(a, b):
      try:
          return a / b
      except ZeroDivisionError:
          return 'Cannot divide by zero!'