Extending class that is in another file

clankill3r

The more I use python the more I dislike it. It seems really great at the start. But so many things are so shit.

Anyway, this works great:

class Foo:
    def __init__(self):
        global BAR
        BAR = -1


class Bananas(Foo):

    def __init__(self):
        Foo.__init__(self)
        print str(BAR)


if __name__ == "__main__":
    b = Bananas()       

But how can I do the same, but having Foo in it's own file?

clankill3r

Here is a slight varation:

my_lib.py:

class Foo:

    BAR = -1

    def __init__(self):
        pass

main.py:

from my_lib import Foo


class Bananas(Foo):

    def __init__(self):
        Foo.__init__(self)
        print str(Foo.BAR)


if __name__ == "__main__":
    b = Bananas()   

But I really don't want to type Foo.BAR but just type BAR! Whatever I try, there is always breaking one things.

GoToLoop

... but just type BAR!

• What you're asking for is ordinarily used a lot in languages such as Java & C#. ~O)
• However it's against what is known as the Zen of Python's principles: [-X
  https://en.Wikipedia.org/wiki/Zen_of_Python
• "Explicit is better than implicit." is the 2nd principle over there btW. ;;)
• BAR is a member of class Foo.
• Therefore you've gotta prefix it w/ Foo. in order to affirm it belongs to that class, and it's not a mere variable or something else. :-\"
• Prefixing w/ parameter self is an alternative to Foo.BAR too: self.BAR
• Anyways, I've already showed ya a hack on how to make sure an imported global variable doesn't lose its original object's reference when using operators w/ = in your previous post: L-)

https://forum.Processing.org/two/discussion/22610/create-a-library-that-can-be-used-global#Item_2

clankill3r

This conflicts with the first one:

Beautiful is better than ugly. I will just use the ugly prefixes then.

GoToLoop

Just to clarify: I do not follow Python's "zenness"! >:)
I very much prefer cleverness over puritanism. :ar!
And I love we don't need to prefix everything w/ this. in Java! ~O)

clankill3r

Also I really love curly braces!

GoToLoop

Hmm... I don't care about curly braces and semicolons. :>

kfrajer

@GoToLoop How do ppl keep track of function scopes without curly brackets? Even if the IDE does some job for you, if you extends beyond the number of line your display can output, how would you match scopes? Are you tie to use specific IDEs? I wonder how would emacs handle python coding...

Kf

GoToLoop

Via indentations! Even simple text editors like NotePad2 keeps the current indentation after an ENTER key press. =P~

jeremydouglass

• https://realpython.com/blog/python/emacs-the-best-python-editor/
• https://emacswiki.org/emacs/PythonProgrammingInEmacs

kfrajer

Hmmm if you have multiple nested if statements... how do you keep track and ensures you are in the right scope? I should probly check it out but I am not keen in working in python at the moment. Having no curly brackets just make my eyes spin 8-|

Kf

GoToLoop

... if you have multiple nested if statements...

Multiple nested branches are bad.
Big sections can be replaced by function calls though.
For really long 1s, switch () / case: is another option.
Although I guess switch () / case: doesn't exist in Python. 3:-O

jeremydouglass

Having no curly brackets just make my eyes spin

"I dunno ... whitespace?"