code: def daily_cash(self):
          '每日交易结算时的现金表'
          res = self.cash_table.drop_duplicates(subset='date', keep='last')
          le=pd.DataFrame(pd.Series(data=None, index=pd.to_datetime(self.trade_range_max).set_names('date'), name='predrop'))
          ri=res.set_index('date')
          res_=pd.merge(le,ri,how='left',left_index=True,right_index=True)
          res_=res_.ffill().fillna(self.init_cash).drop(['predrop','datetime','account_cookie'], axis=1).reset_index().set_index(['date'],drop=False).sort_index()        
          res_=res_[res_.index.isin(self.trade_range)]
          return resf daily_cash(self):
          '每日交易结算时的现金表'
          res = self.cash_table.drop_duplicates(subset='date', keep='last')
          le=pd.DataFrame(pd.Series(data=None, index=pd.to_datetime(self.trade_range_max).set_names('date'), name='predrop'))
          ri=res.set_index('date')
          res_=pd.merge(le,ri,how='left',left_index=True,right_index=True)
          res_=res_.ffill().fillna(self.init_cash).drop(['predrop','datetime','account_cookie'], axis=1).reset_index().set_index(['date'],drop=False).sort_index()        
          res_=res_[res_.index.isin(self.trade_range)]
          return res_
docs: 每日交易结算时的现金表