x.py

import pathlib

import attr
import PyQt5.uic


Ui, UiBase = PyQt5.uic.loadUiType(
    pathlib.Path(__file__).with_suffix('.ui'),
)


@attr.s
class FilesView(UiBase):
    ui = attr.ib(factory=Ui)

    @classmethod
    def build(cls, parent):
        instance = cls()
        instance.setParent(parent)

        return instance

    def __attrs_post_init__(self):
        super().__init__()

        if self.ui is not None:
            self.ui.setupUi(self)