如何在Python中编写具有输出参数（按引用调用）的函数？

# Function Definitiondef demo(val1, val2):   val1 = 'new value'   val2 = val2 + 1   return val1, val2x, y = 'old value', 5# Function callprint(demo(x, y))

('new value', 6)

# Function Definitiondef demo2(a):   # 'a' references a mutable list   a[0] = 'new-value'   # This changes a shared object   a[1] = a[1] + 1args = ['old-value', 5]demo2(args)print(args)

['new-value', 6]

def demo3(args):   # args is a mutable dictionary   args['val1'] = 'new-value'   args['val2'] = args['val2'] + 1args = {'val1': 'old-value', 'val2': 5}# Function calldemo3(args)print(args)

class Namespace:   def __init__(self, **args):      for key, value in args.items():         setattr(self, key, value)def func4(args):   # args is a mutable Namespace   args.val1 = 'new-value'   args.val2 = args.val2 + 1args = Namespace(val1='old-value', val2=5)# Function Callfunc4(args)print(vars(args))