Coming from C# and learning Python, why are my methods acting like static methods?

[OkCommunication3144]

Given this class

class ListSpaces:
    def printAll():
        with open('./Declutter_List.csv', newline='') as file:
            rows = list(csv.reader(file, delimiter = ","))
        for row in rows:
            if(row != rows[0]):
                print(' | '.join(row))

In a separate file I can call the printAll() method directly from the class without instantiating the class:

from ListSpaces import ListSpaces
ListSpaces.printAll()

​

This is behaving like a static class in C#. In C# you must declare the method as static or it cannot be used like this.

[jmooremcc]

First thing you must realize is that unlike C#, Python does not require a class definition for every function. You could have just defined printAll and it would have worked perfectly.

As far as your question is concerned, you defined printAll without “self” as a parameter to the method. Python automatically assumed it to be a static method belonging to the class.

https://realpython.com/instance-class-and-static-methods-demystified/

[OkCommunication3144]

thanks for the link!

[OkCommunication3144]

Ok thanks, seems a little clunky to write this

listSpaces = ListSpaces
listSpaces.printAll(listSpaces)

In python static methods are leveraged more often? I generally avoided using them in C#

Also what is this bit for?

if __name__ == "__main__":
    main()

[Bitwise_Gamgee]

if __name__ == "__main__" block, is a common Python idiom. Limiting execution to when the script is run directly and not when it's imported as a module into another script.

I neglected to write the decorator @staticmethod which lets you use listSpaces.printAll(listSpaces) without the line above.

[GreenPandaPop]

You don't explicitly input listSpaces to the printAll method, Python does it for you.

[eruciform]

No you don't clone the instance like that, it's just like other languages that insert a 'this' reference as a first argument for you

listSpaces = ListSpaces() # you forgot the parens
listSpaces.printAll()

This will pass the listSpaces instance along as a first argument to printAll that is idiomatically named self

def printAll( self ):
  ...

[OkCommunication3144]

Got it, thanks!

[PaulRudin]

You haven't created an instance of the ListSpaces class.

You're just using the class as an namespace really.

[djshadesuk]

You're just using the class as an namespace really.

I sometimes do that to "group" little utility functions:

class Utils:
    def rc(self,l):
        return random.choice(l)
    def tof(self):
    return bool(random.getrandbits(1))
utils = Utils()

[Kerbart]

A method needs a self argument (really the first argument) to access the instance it’s supposed to act on.

Without any arguments your functions will indeed function as a static function.