Ensure instances become immutable after their creation.
This is achieved by using isfrozen attribute to True after the instance is created, preventing further modifications to its attributes.
>>> doc = ImmutableDocument(
>>> author="Alice",
>>> filename="Doc1.txt",
>>> content="a cool content",
>>> date=datetime.date(2024, 1, 1),
>>> filetype="txt")
>>> print(doc.author)
> "Alice"
>>> doc.author = "Bob" # Raises AttributeError
>>> del doc.author # Raises AttributeError
def __init__(self, author: str, filename: str, date: datetime.date | datetime.datetime | None=None, content: str | bytes='', description: str='', downloads: int=0):
self._is_frozen = False
self.author = DocumentUtils.format_author(author)
self.content = content
self.date = date
self.description = description
self.filename = DocumentUtils.format_filename(filename)
self.filetype = DocumentUtils.get_filetype(filename)
self.downloads = downloads
self._is_frozen = True
Return the name of the folder in which the document is stored.
The folder_name can be used for both:
def get_folder_name(self) -> str:
"""Return the name of the folder in which the document is stored.
The folder_name can be used for both:
- an identifier for the document, and
- get information about the document: author, filename, date and filetype
"""
return DocumentUtils.get_folder_name(self.author, self.filename, self.date, self.filetype)
def to_immutable(self) -> ImmutableDocument:
return self
Override to prevent any attribute setter.
def __setattr__(self, key, value):
"""Override to prevent any attribute setter."""
if getattr(self, '_is_frozen', False):
raise AttributeError(f'{self.__class__.__name__} object is immutable')
super().__setattr__(key, value)
Override to prevent any attribute deletion.
def __delattr__(self, key):
"""Override to prevent any attribute deletion."""
if getattr(self, '_is_frozen', False):
raise AttributeError(f'{self.__class__.__name__} object is immutable')
super().__delattr__(key)
def __str__(self):
return f'ImmutableDocument({self.author}, {self.filename}, {self.date}, {self.filetype})'
def __repr__(self):
return f'ImmutableDocument(author={self.author}, filename={self.filename}, date={self.date}, filetype={self.filetype})'