私は、以下のようにいくつかのプリミティブと配列型のプロパティを持つデータモデル持っているのpython

Question

でのモデルとは異なり、レコードの挿入を防止する方法：いくつかのハック来る

class WordCollection: 
    """First model""" 
    def __init__(self, **properties): 
     self.name = "" 
     self.status = CommonStatus.active 
     self.expire_time = time.time() + 1000 * 60 * 24 # after 1 day 
     self.created_date = time.time() 
     self.words = [] 
     self.__dict__.update(properties) 

を。例えば、クラスの一部ではないプロパティでクラスを構築する場合、簡単にハックすることができます。

collection = WordCollection(**{..., "hack_property":"large text or irrelative data"}) 

ので、私はクラスにプレイしたメソッドを初期化します。

class WordCollection: 
     """Second model""" 
     def __init__(self, **properties): 
      self.name = properties["name"] if "name" in properties else "" 
      self.status = properties["active"] if "active" in properties else CommonStatus.active 
      self.expire_time = properties["expire_time"] if "expire_time" in properties else time.time() + 1000 * 60 * 24 # after 1 day 
      self.created_date = properties["created_date"] if "created_date" in properties else time.time() 
      self.words = properties["words"] if "words" in properties else [] 

しかし、上記のコードは、完全な形で問題を解決しない：

：

collection = WordCollection(**{..., "name":{"hack_property":"large text or irrelative data"}}) 

これが最後の再構築コードです

class WordCollection: 
     """Third Model""" 
     def __init__(self, **properties): 
      self.name = properties["name"] if "name" in properties and isinstance(properties["name"], str) else "" 
      self.status = properties["active"] if "active" in properties \ 
                and isinstance(properties["status"], int) else CommonStatus.active 
      .... 

上記の改訂履歴それは条件付きの複雑さをもたらし、私はそれがより良い解決策であると信じています。

Answer 1

より標準的な処方：

valid_properties = {'prop1', 'prop2', 'prop3'} 
class WordCollection(object): 
    def __init__(self, name="", status=None; **properties): 
     # This one is explicit, with a default that is specified in the call signature 
     # Defaults in the call signature are resolved when the class is imported 
     self.name = name 
     # This one is more dynamic - CommonStatus.active could change 
     # after the user imports the class, so we don't want it fixed. 
     # Instead, use a sentinel. 
     # I usually use None. If None is a valid value, best bet 
     # is to do something like this: 
     # sentinel = object() 
     # then use that instead of None. 
     self.status = CommonStatus.active if status is None else status 
     # This one we just assign - 
     self.words = [] 
     # You don't _have_ to include a **kwargs if you don't want to. 
     # If you don't want _any_ surprise properties, just leave 
     # **properties out of the __init__, and only ones you explicit 
     # declare will be allowed. 
     # Explicit is better - they show up in tab completion/help 
     # But if you want to filter out input to a set of valid props... 
     filtered_props = {k:v for k,v in properties.items() if k in valid_properties} 
     self.__dict__.update(filtered_props)