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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def show(self, rows: int=5, dataframe: pd.DataFrame=None) -> pd.DataFrame: """ Display info about the dataframe :param rows: number of rows to show, defaults to 5 :param rows: int, optional :param dataframe: a pandas dataframe, defaults to None :param dataframe: pd.DataFrame, optional :return: a pandas dataframe :rtype: pd.DataFrame :example: ``ds.show()`` """

        try:
            if dataframe is not None:
                df = dataframe
            else:
                df = self.df
            if df is None:
                self.warning("Dataframe is empty: nothing to show")
                return
            num = len(df.columns.values)
        except Exception as e:
            self.err(e, self.show, "Can not show dataframe")
            return
        f = list(df)
        fds = []
        for fi in f:
            fds.append(str(fi))
        fields = ", ".join(fds)
        num_rows = len(df.index)
        self.info("The dataframe has", colors.bold(num_rows), "rows and",
                  colors.bold(num), "columns:")
        print(fields)
        return df.head(rows)