How to use the simpleeval.DEFAULT_FUNCTIONS.copy function in simpleeval

def test_functions_are_disallowed_in_expressions(self):
        DISALLOWED = [type, isinstance, eval, getattr, setattr, help, repr, compile, open]

        if simpleeval.PYTHON3:
            exec('DISALLOWED.append(exec)') # exec is not a function in Python2...

        for f in simpleeval.DISALLOW_FUNCTIONS:
            assert f in DISALLOWED


        DF = simpleeval.DEFAULT_FUNCTIONS.copy()

        for x in DISALLOWED:
            simpleeval.DEFAULT_FUNCTIONS = DF.copy()
            with self.assertRaises(FeatureNotAvailable):
                s = SimpleEval()
                s.functions['foo'] = x
                s.eval('foo(42)')

        simpleeval.DEFAULT_FUNCTIONS = DF.copy()

print()


def double(x):
    return x * 2


my_functions = {
    "d": double,
    "double": double
}
print(simple_eval("d(100) + double(1)", functions=my_functions))  # 202


import simpleeval
my_functions = simpleeval.DEFAULT_FUNCTIONS.copy()
my_functions.update(
    square=lambda x: x * x,
    double=lambda x: x * 2,
)
print(simple_eval('square(randint(100))', functions=my_functions))  # 1024

def set_parent(self, parent):
        self._effect.set_parent(parent._effect)


class AliasException(AvraeException):
    pass


def raise_alias_exception(reason):
    raise AliasException(reason)


DEFAULT_OPERATORS = simpleeval.DEFAULT_OPERATORS.copy()
DEFAULT_OPERATORS.pop(ast.Pow)
DEFAULT_FUNCTIONS = simpleeval.DEFAULT_FUNCTIONS.copy()
DEFAULT_FUNCTIONS.update({'floor': floor, 'ceil': ceil, 'round': round, 'len': len, 'max': max, 'min': min,
                          'range': safe_range, 'sqrt': sqrt, 'sum': sum, 'any': any, 'all': all,
                          'roll': simple_roll, 'vroll': verbose_roll, 'load_json': load_json, 'dump_json': dump_json,
                          'time': time.time, 'err': raise_alias_exception})

if __name__ == '__main__':
    evaluator = ScriptingEvaluator()
    while True:
        try:
            evaluator.eval(input("Evaluate: ").strip())
        except Exception as e:
            print(e)
            continue
        print(evaluator.names)