详解python函数传参传递dict/list/set等类型的问题

def trans(var):
  return var

source = {1: 1}
dist = trans(source)
source[2] = 2
print(source)
print(dist)

global dataset
dataset = {}

class Config(object):
  def __init__(self, device_url):
    self.device_url = device_url
  
  def get_config(self, key):
    global dataset
    
    if key in dataset:
      return dataset.get(key)
    else:
      # 通过device_url从设备获取配置，假如赋值给了value
      dataset[key] = value
      return value
    
  def other_func(self):
    # 其他函数，跟device_url有关
    pass

class Config(object):
  
  def __init__(self, dataset, device_url):    # 传递可变对象dataset
    self.dataset = dataset
    self.device_url = device_url
  
  def get_config(self, key)：    
    if key in self.dataset:
      return self.dataset.get(key)
    else:
      # 通过device_url从设备获取配置，假如赋值给了value
      self.dataset[key] = value    # 可变对象dataset赋值，其他实例化的dataset属性值也会变化
      return value
    
  def other_func(self):
    # 其他函数，跟device_url有关
    pass

config1 = Config({})
config2 = Config({})
config1.dataset[1] = 1
print(repr(config1.dataset))
print(repr(config2,dataset))

share_var = {}
config1 = Config(share_var)
config2 = Config(share_var)
config1.dataset[1] = 1
print(repr(config1.dataset))
print(repr(config2,dataset))

def func1(mutable_object, flag):
  if flag:
    return mutable_object
  else:
    return {}

def func2(mutable_object):
  # something to do with mutable_object
  pass

func2(func1(mutable_object, False)) # 此处func1(mutable_object, False)返回的是{}，是一个不可变对象