def update(self) -> None:
    df = pd.read_csv(self.csv_file_path, parse_dates=['Date'])
    for area in df['Area']:
        if (area in self.area_list):
            break
        self.area_list.append(area)
    df = df.pivot(index='Date', columns='Area', values='New Cases')
    self._df = df[self.area_list]
def update(self) -> None:
    df = pd.read_csv(self.csv_file_path, parse_dates=['Date'])
    for area in df['Area']:
        if (area in self.area_list):
            break
        self.area_list.append(area)
    df = df.pivot(index='Date', columns='Area', values='New Cases')
    self._df = df[self.area_list]