Repository: ManimCommunity/manim
File: manim/mobject/graphing/probability.py (Python)

Code before:
        self.bar_colors = bar_colors
        self.bar_width = bar_width
        self.bar_fill_opacity = bar_fill_opacity
        self.bar_stroke_width = bar_stroke_width

        x_range = [0, len(self.values), 1]

        if y_range is None:
            y_range = [
                min(0, min(self.values)),
                max(0, max(self.values)),
                round(max(self.values) / y_length, 2),
            ]
        elif len(y_range) == 2:
            y_range = [*y_range, round(max(self.values) / y_length, 2)]

        if x_length is None:
            x_length = min(len(self.values), config.frame_width - 2)

        x_axis_config = {"font_size": 24, "label_constructor": Tex}
        self._update_default_configs(
            (x_axis_config,), (kwargs.pop("x_axis_config", None),)
        )

        self.bars: VGroup
        self.x_labels: VGroup
        self.bar_labels: VGroup

        super().__init__(
            x_range=x_range,
            y_range=y_range,
            x_length=x_length,
            y_length=y_length,
            x_axis_config=x_axis_config,
            tips=kwargs.pop("tips", False),
            **kwargs,
        )

        self._add_bars()

        if self.bar_names is not None:
            self._add_x_axis_labels()

        self.y_axis.add_numbers()

    def _update_colors(self):
        """Initialize the colors of the bars of the chart.

        Sets the color of ``self.bars`` via ``self.bar_colors``.

        Primarily used when the bars are initialized with ``self._add_bars``

Review comment (suggestion):
I find this change rather suspicious. Because it removes the default value for the attribute so that it basically doesn't exist. I would change this to `self.x: Optional[VGroup] = None` for the three attributes because else it changes functionality.

Code after:
            bar_colors = list(bar_colors)

        y_length = y_length if y_length is not None else config.frame_height - 4

        self.values = values
        self.bar_names = bar_names
        self.bar_colors = bar_colors
        self.bar_width = bar_width
        self.bar_fill_opacity = bar_fill_opacity
        self.bar_stroke_width = bar_stroke_width

        x_range = [0, len(self.values), 1]

        if y_range is None:
            y_range = [
                min(0, min(self.values)),
                max(0, max(self.values)),
                round(max(self.values) / y_length, 2),
            ]

        elif len(y_range) == 2:
            y_range = [*y_range, round(max(self.values) / y_length, 2)]

        if x_length is None:
            x_length = min(len(self.values), config.frame_width - 2)

        x_axis_config = {"font_size": 24, "label_constructor": Tex}
        self._update_default_configs(
            (x_axis_config,), (kwargs.pop("x_axis_config", None),)
        )

        self.bars: VGroup = VGroup()
        self.x_labels: VGroup | None = None
        self.bar_labels: VGroup | None = None

        super().__init__(
            x_range=x_range,
            y_range=y_range,
            x_length=x_length,
            y_length=y_length,
            x_axis_config=x_axis_config,
            tips=kwargs.pop("tips", False),
            **kwargs,
        )

        self._add_bars()

        if self.bar_names is not None:
            self._add_x_axis_labels()

        self.y_axis.add_numbers()