pandas.DataFrame.loc 不适用于索引日期

Question

I'm trying to look for a piece of data by date and value, however, I keep getting an error. Here is the code:

eth.loc['2020-08-13', 'Value']

Here is the error:

        352                 except ValueError as err:
        353                     raise KeyError(key) from err
    --> 354             raise KeyError(key)
        355         return super().get_loc(key, method=method, tolerance=tolerance)
        356 
    
    KeyError: '2020-08-13'

Thanks!

Answer 1

Assumming you've a dataset defined by:

eth = pd.DataFrame([['2020-08-13', 2], ['2020-08-14', 5], ['2020-08-15', 8]], 
                    index=['book1','book2','book3'], 
                    columns=['Date','Value'])

You can get items with value say 2:

eth.loc[eth['Value'] == 2]

You can get items with date say 2020-08-13:

eth.loc[eth['Date'] == '2020-08-13']

Answer 2

Answer turned out to be eth.loc[eth.columnname=='2020-08-13', 'Value'] , thanks to @wwnde for the help!