Can a class attribute shadow a built-in in Python?

Question

If have some code like this:

class Foo():
   def open(self, bar):
       # Doing some fancy stuff here, i.e. opening "bar"
       pass

When I run flake8 with the flake8-builtins plug-in I get the error

A003 class attribute "open" is shadowing a python builtin

I don't understand how the method could possibly shadow the built-in open-function, because the method can only be called using an instance (i.e. self.open("") or someFoo.open("")). Is there some other way code expecting to call the built-in ends up calling the method? Or is this a false positive of the flake8-builtins plug-in?

Answer 1

Not really a practical case, but your code would fail if you wanted to use the built-it functions on the class level after your shadowed function has been initialized:

class Foo:
    def open(self, bar):
        pass

    with open('myfile.txt'):
        print('did I get here?')

>>> TypeError: open() missing 1 required positional argument: 'bar'

The same would also be true with other built-in functions, such as print

class Foo:
    def print(self, bar):
        pass

    print('did I get here?')

>>> TypeError: print() missing 1 required positional argument: 'bar'