I’m learning object oriented programing in a data science context. I want to understand what good practice is in terms of writing methods within a class that relate to one another. When I run my code: I get the following output (only part of the output is shown due to space constrains): I am happy with …
Tag: oop
can anyone explain what “out = self(images)” do in below code
I am not able to understand, if prediction is calculated in forward method, then why there is need “out = self(images)” and what it will do. I am bit confuse about this code. model = MnistModel() Answer In Python, self refers to the instance that you have created from a class (similar to this in J…
How to check if string exists in Enum of strings?
I have created the following Enum: I have inherited from str, too, so that I can do things such as: I would now like to be able to check if a string is in this Enum, such as: I have tried adding the following method to the class: However, when I run this code: I get this exception: Answer I
Using Tkinter, Threading and After method
im working on a selenium project using tkinter in python. I want to execute many selenium task at one time(could be up to 100), so I used threading to accomplish this goal, but I came to a problem, due to the fact that I need all individual selenium task to wait a couple seconds between instructions, I used t…
KeyError for multiframe tkinter?
I keep getting a KeyError and I am unsure why. I added a print statement and printed the self.frames dict to ensure that the keys existed, and it appears they do. I’m new to using classes to create multi frame apps so any insight would be helpful. The error: The dict that prints: The code where the erro…
How can I get multiple dataframes returned from a class function?
So I have made a class that takes in a ticker symbol, and it returns a dataframe with all the price information for the dates specified. here is the code below: now this works perfectly, but ideally id like to pass in a list of symbols and have it return a seperate df for each symbol. so for example, symbols
Abstract dataclass without abstract methods in Python: prohibit instantiation
Even if a class is inherited from ABC, it can still be instantiated unless it contains abstract methods. Having the code below, what is the best way to prevent an Identifier object from being created: Identifier([‘get’, ‘Name’])? Answer You can create a AbstractDataclass class which gu…
Get value of related object by list of fields in @property
I have two model like this with following fields: I Also I have this list of fields name: And finally I want to I create this @property: But for related objects this isn’t the correct way and I got this error: ‘Profile’ object has no attribute ‘address.postal_code’ How Can I use …
How do I create a class where instantiation only happens if certain conditions are met?
Let’s say I have this class: If I want to instantiate Person I can do: But what if I only want to instantiate Person if name has type str? I tried this: But then when I do: I get this: So all that’s happening is: If name is str, the instance has a .name method If name is not str,
When are static variables initialized in Python?
Consider the following code When exactly does the initialization of i take place? Before the execution of the init method or after it? Answer Before. The __init__ method isn’t run until Foo is instantiated. i=1 is run whenever the class definition is encountered in the code You can see this by adding pr…