code: def operator_from_str(op):
      
      d = {"==": operator.eq,
           "!=": operator.ne,
           ">": operator.gt,
           ">=": operator.ge,
           "<": operator.lt,
           "<=": operator.le,
           '+': operator.add,
           '-': operator.sub,
           '*': operator.mul,
           '%': operator.mod,
           '^': operator.xor,
           }
  
      try:
          d['/'] = operator.truediv
      except AttributeError:
          pass
  
      return d[op]
docs: Return the operator associated to the given string `op`.
  
      raises:
          `KeyError` if invalid string.
  
      >>> assert operator_from_str("==")(1, 1) and operator_from_str("+")(1,1) == 2