如何使类的默认返回值成为字典

Question

I hope the title is clear enough for my purpose, to be honest I did not try much because I didn't really knew where to go to, and I'm not even sure this is totally possible. I know its possible to override __str__ and __int__ to return values of those 2 types. I sure you're asking 'why not have a class function to return what you want', and sure its a reasonable question, but I wanted a cleaner way to do it.

I've searched for other similar questions and examples that might have helped but none really do what I intend. The closest I could get is from the example I tried below overriding __new__ and __repr__ .

class student:
    def __init__(self, name, age):
        self.info = {'name': name, 'age': age}
    def __new__(self, name, age):
        return self.info
    def __repr__(self, name, age):
        return self.info
student_data = student('Rob', 18)

print(student_data)

Thanks in advance

Answer 1

You were close. Both __str__ and __repr__ must return a string. print will internally call your object's __str__ representation. So, just have your __str__ method return the string representation of self.info (IOW str(self.info) ).

class Student:
    def __init__(self, name, age):
        self.info = {'name': name, 'age': age}

    def __repr__(self):
        return str(self.info)

    def __str__(self):
        return self.__repr__()

student_data = Student('Rob', 18)
print(student_data)
# {'name': 'Rob', 'age': 18}

Answer 2

If your goal is to make an object act like a dictionary, you can subclass dict itself, or perhaps even easier, subclass collections.UserDict .

import collections

class Student(collections.UserDict):
    def __init__(self, name, age):
        self.data = {'name': name, 'age': age}

student_data = Student('Rob', 18)

print(student_data)