Represent Python Class As Dictionary
Represent a class by a dictionary: the class attributes became the dictionary keys and the attributes values the dictionary values.
Solution
Explanation
In Python, when a class is evaluated the method __repr__ is called and it can only return the string type. If you try to return anything different an exception is raised:
But Dictionary(dict) is a built-in type/class and it is represented by a dictionary (obviously)…
The solution consisted in:
1 — Make a class inherit from the dict class
2 — Overwrite the __repr__ method setting the dictionary keys and values with the __setitem__ method and return the super().__repr__, which can return dicts.
I couldn’t make my class work like a dict without inheriting from it, if you can please share your solution in the comments ;).
Как преобразовать список в словарь в Python
Существует множество способов интерпретации данных в списке, как ключей и значений, и преобразования этого списка в словарь.
- [ключ_1, значение_1, ключ_2, значение_2,…] – Ключ: пары значений как непрерывные элементы списка.
- [key_1, key_2, â € ¦], [value_1, value_2, â € ¦] â € «Ключи находятся в одном списке, а значения – в другом списке.
- [(ключ_1, значение_1), (ключ_2, значение_2),…] Ключ: пары значений как кортежи, и эти кортежи являются элементами списка.
- Преобразование списка в словарь с элементом списка в качестве ключа и индексом в качестве значения.
- Преобразование списка в словарь с элементом списка в качестве ключа, и значением по умолчанию.
В этом руководстве мы узнаем, как преобразовать эти форматы списков в словарь с помощью хорошо подробных примеров программ.
Пример 1
В этом примере мы преобразуем список формата [key_1, value_1, key_2, value_2, â € ¦] в словарь
Мы будем использовать понимание словаря, чтобы преобразовать этот тип списка в словарь.
Пример 2: преобразование списка ключей
В этом примере мы преобразуем список формата [(key_1, value_1), (key_2, value_2), â € ¦] в словарь
Мы будем использовать понимание словаря, чтобы преобразовать эти списки ключей и значений в словарь.
Пример 3: преобразование списка кортежей
В этом примере мы преобразуем список формата [(key_1, value_1), (key_2, value_2), â € ¦] в словарь
Мы будем использовать понимание словаря для преобразования списка кортежей в словарь.
Пример 4: с индексом
В этом примере мы преобразуем список формата [key_1, key_2, â € ¦] в словарь
Пример 5: значение по умолчанию
В этом примере мы преобразуем список формата [key_1, key_2, â € ¦] в словарь
Python object and dictionary convertion
When programing in Python, sometimes you want to convert an object to dictionary and vise versal. In this article, I share my expericences to do that.
Convert from class to dictionary
When you want to convert a class to dictionary just define class override from object (this is important) and then call method __dict__ :
Convert from dictionary to class
In contrast, if you want to convert a dictionary to object, use this method. I did not invent this method, it is borrowed from stackoverflow.com)
I change above methods like bellow to get recusive convertion dictionary:
In python, how do I cast a class object to a dict
What do I need to define for this to work? I tried substituting both __dict__ and dict for __what_goes_here__ , but dict(w) resulted in a TypeError: Wharrgarbl object is not iterable in both cases. I don’t think simply making the class iterable will solve the problem. I also attempted many googles with as many different wordings of «python cast object to dict» as I could think of but couldn’t find anything relevant :<
Also! Notice how calling w.__dict__ won’t do what I want because it’s going to contain w.version and w.sum . I want to customize the cast to dict in the same way that I can customize the cast to int by using def int(self) .
I know that I could just do something like this
But I am assuming there is a pythonic way to make dict(w) work since it is the same type of thing as int(w) or str(w) . If there isn’t a more pythonic way, that’s fine too, just figured I’d ask. Oh! I guess since it matters, this is for python 2.7, but super bonus points for a 2.4 old and busted solution as well.
There is another question Overloading __dict__() on python class that is similar to this one but may be different enough to warrant this not being a duplicate. I believe that OP is asking how to cast all the data in his class objects as dictionaries. I’m looking for a more customized approach in that I don’t want everything in __dict__ included in the dictionary returned by dict() . Something like public vs private variables may suffice to explain what I’m looking for. The objects will be storing some values used in calculations and such that I don’t need/want to show up in the resulting dictionaries.
UPDATE: I’ve chosen to go with the asdict route suggested but it was a tough choice selecting what I wanted to be the answer to the question. Both @RickTeachey and @jpmc26 provided the answer I’m going to roll with but the former had more info and options and landed on the same result as well and was upvoted more so I went with it. Upvotes all around though and thanks for the help. I’ve lurked long and hard on stackoverflow and I’m trying to get my toes in the water more.