def __call__(self, df):
    extra_fields = df.schema.fields[len(self.df.schema.fields):]
    lhs = self.df._yield_pdf()
    return pandas.concat(([lhs] + [eval_column(df, lhs, col).rename(i) for (i, (_, col)) in enumerate(self.name_col_pairs, len(self.df.columns))]), axis=1)
def __call__(self, df):
    extra_fields = df.schema.fields[len(self.df.schema.fields):]
    lhs = self.df._yield_pdf()
    return pandas.concat(([lhs] + [eval_column(df, lhs, col).rename(i) for (i, (_, col)) in enumerate(self.name_col_pairs, len(self.df.columns))]), axis=1)