coding-mentor-agent/kb/python-course-kb-practical-python/wiki/exercises/5-8-adding-slots.md

id, source_exercise_id, title, section, source_path, source_repo, source_commit, student_visible_solution, has_private_solution, skip

id	source_exercise_id	title	section	source_path	source_repo	source_commit	student_visible_solution	has_private_solution	skip
practical-python-5.8	5.8	Adding slots	5.2 Classes and Encapsulation	05_Object_model/02_Classes_encapsulation.md	https://github.com/dabeaz-course/practical-python	93dca856b41c61a0a0f85ae334116e4c125629ea	false	true	false

Exercise 5.8: Adding slots

Source: Practical Python Programming, 05_Object_model/02_Classes_encapsulation.md.

Exercise 5.8: Adding slots

Modify the Stock class so that it has a __slots__ attribute. Then, verify that new attributes can't be added:

>>> ================================ RESTART ================================
>>> from stock import Stock
>>> s = Stock('GOOG', 100, 490.10)
>>> s.name
'GOOG'
>>> s.blah = 42
... see what happens ...
>>>

When you use __slots__, Python uses a more efficient internal representation of objects. What happens if you try to inspect the underlying dictionary of s above?

>>> s.__dict__
... see what happens ...
>>>

It should be noted that __slots__ is most commonly used as an optimization on classes that serve as data structures. Using slots will make such programs use far-less memory and run a bit faster. You should probably avoid __slots__ on most other classes however.

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关联来源

• summaries/02_Classes_encapsulation