geom.py 文件源码

def use_defaults(self, data):
        """
        Combine data with defaults and set aesthetics from parameters

        geoms should not override this method.

        Parameters
        ----------
        data : pandas.DataFrame
            Data used for drawing the geom.

        Returns
        -------
        out : pandas.DataFrame
            Data used for drawing the geom.
        """
        missing_aes = (six.viewkeys(self.DEFAULT_AES) -
                       six.viewkeys(self.aes_params) -
                       set(data.columns))

        # Not in data and not set, use default
        for ae in missing_aes:
            data[ae] = self.DEFAULT_AES[ae]

        # If set, use it
        for ae, value in self.aes_params.items():
            try:
                data[ae] = value
            except ValueError:
                # sniff out the special cases, like custom
                # tupled linetypes, shapes and colors
                if is_valid_aesthetic(value, ae):
                    data[ae] = [value]*len(data)
                else:
                    msg = ("'{}' does not look like a "
                           "valid value for `{}`")
                    raise PlotnineError(msg.format(value, ae))

        return data