+ 2

Is it possible to inherit from a class in __init__ instead of: class Child(Parent):

The problem is that I want to pass a value to the constructor and based on the type of value I want to inherit from the type class of that value. Let's say I pass a str type object then my class should inherit from str. Is there a way?

29th Jul 2020, 2:31 PM
Ali Abdelhady
Ali Abdelhady - avatar
12 Answers
+ 4
Okay, I think I've found a way. check it out below. Doesn't work with bool though because bool doesn't seem to allow inheritance. https://code.sololearn.com/cBjVQ8P3Lr7f/?ref=app
30th Jul 2020, 12:13 PM
HonFu
HonFu - avatar
+ 3
https://code.sololearn.com/c64BzvL68mD7/?ref=app Here is the code
29th Jul 2020, 11:00 PM
Ali Abdelhady
Ali Abdelhady - avatar
+ 3
I would set up eq, repr and str like this: def __eq__(self, other): return ( isinstance(other, Restrictive) and type(self.val) == type(other.val) and self.val == other.val ) def __repr__(self): return f"Restrictive({repr(self.val)})" def __str__(self): return str(repr(self.val)) If I try this... a, b, c, d, e = ( Restrictive(i) for i in (5, 1, 1, True, '5') ) s = {a, b, c, d, e} print(s) ... it seems to already work. I'm still unsure what you mean with the inheriting. I see nothing of that in your code example or task specification. I mean, you're not inheriting, you're storing a value of a different type in an instance.
30th Jul 2020, 7:47 AM
HonFu
HonFu - avatar
+ 2
Can you maybe describe your intended use case? (It sounds like there might be an easier way.)
29th Jul 2020, 10:37 PM
HonFu
HonFu - avatar
+ 2
HonFu Well basically I am trying to create a container for data types that overrides both __hash__ and __eq__ All it does is that it compares types restrictively, more like the === in JS. And of course, it is usable as a key in dictionaries and can be used inside a set. Anything else behaves as usual so, False != 0 But both of them behave like a regular bool and int objects.
29th Jul 2020, 10:47 PM
Ali Abdelhady
Ali Abdelhady - avatar
+ 2
Hmmmmmmmm. đŸ€”
30th Jul 2020, 11:50 AM
HonFu
HonFu - avatar
+ 1
Can I ask for help? HonFu Oma Falk
29th Jul 2020, 10:27 PM
Ali Abdelhady
Ali Abdelhady - avatar
+ 1
HonFu I want it to work with its own type as well as built in types, so that I can say: Restrictive(False) == 0 # False Restrictive (True) == True # True Restrictive (1) == Restrictive(1) # True The code already works, the problem is that I want it to support any other built-in type method So if self.val = 'Hello' I want self to support string concatenation and behaves like a regular string. Inheriting can only be done after the value is known.
30th Jul 2020, 11:05 AM
Ali Abdelhady
Ali Abdelhady - avatar
+ 1
So you want to be able to write something like this? a = Restrictive(5) b = Restrictive('hi') print(a*b) # output: hihihihihi
30th Jul 2020, 11:33 AM
HonFu
HonFu - avatar
+ 1
I searched for a method, but found nothing. How does Child(Parent), way works? Is it a class method? If so, can't we just do it manually? However, it doesn't seem to be like that...
30th Jul 2020, 11:54 AM
Ali Abdelhady
Ali Abdelhady - avatar
+ 1
HonFu Thanks a lot!!!
30th Jul 2020, 12:21 PM
Ali Abdelhady
Ali Abdelhady - avatar
0
HonFu Yes!
30th Jul 2020, 11:49 AM
Ali Abdelhady
Ali Abdelhady - avatar