code: def get_transactions(self, include_investment=False):
          
          assert_pd()
          s = StringIO(self.get_transactions_csv(
              include_investment=include_investment))
          s.seek(0)
          df = pd.read_csv(s, parse_dates=['Date'])
          df.columns = [c.lower().replace(' ', '_') for c in df.columns]
          df.category = (df.category.str.lower()
                         .replace('uncategorized', pd.np.nan))
          return df
docs: Returns the transaction data as a Pandas DataFrame.