date sorting.py

    # date sorting -->
    df['date'] = date_list
    form = (lambda date: datetime.strptime(date, "%m/%d/%Y"))
    
    # sorting chronologically -->
    df['index'] = sorted(range(len(date_list)), key=lambda x : form(date_list[x]))
    
    # removing med notes column -->
    df.drop('text', axis=1,inplace=True)
    
    # final sorted series indices --> 
    final = list(df['index'])
    final_series = pd.Series(final)