highpost
highpost

Reputation: 1323

MultiIndex and DateTime

I have a sorted CSV dataset with four columns that I want to use as a MultiIndex, including two DateTime columns:

Alex,Beta,2011-03-01 00:00:00,2011-03-03 00:00:00,A,8,11.4
Alex,Beta,2011-03-03 00:00:00,2011-03-05 00:00:00,B,10,17.2
Alex,Beta,2011-03-05 00:00:00,2011-03-07 00:00:00,A,3,11.4
Alex,Beta,2011-03-07 00:00:00,2011-03-09 00:00:00,B,7,17.2
Alex,Orion,2011-03-02 00:00:00,2011-03-04 00:00:00,A,4,11.4
Alex,Orion,2011-03-03 00:00:00,2011-03-05 00:00:00,B,6,17.2
Alex,Orion,2011-03-04 00:00:00,2011-03-06 00:00:00,A,3,11.4
Alex,Orion,2011-03-05 00:00:00,2011-03-07 00:00:00,B,11,17.2
Alex,ZZYZX,2011-03-02 00:00:00,2011-03-05 00:00:00,A,10,11.4
Alex,ZZYZX,2011-03-04 00:00:00,2011-03-07 00:00:00,A,15,11.4
Alex,ZZYZX,2011-03-06 00:00:00,2011-03-09 00:00:00,B,20,17.2
Alex,ZZYZX,2011-03-08 00:00:00,2011-03-11 00:00:00,B,5,17.2

I can load this with read_csv and display the DataFrame hierarchically. But indexing it is another matter. The nearest I can tell is that pandas doesn't like using DateTime indexes here. If I comment out the DateTime labels in index_col as well as the corresponding entries in the indexing statement (df.loc), it works fine.

Any ideas?

#!/usr/bin/env python

import numpy as np
import pandas as pd

pd.set_option('display.height',            400)
pd.set_option('display.width',             400)
pd.set_option('display.max_rows',         1000)
pd.set_option('display.max_columns',        30)
pd.set_option('display.line_width',        200)

try:
    df = pd.read_csv(
        './sales.csv',
        header =                          None,
        na_values =                   ['NULL'],
        names = [
            'salesperson',
            'customer',
            'invoice_date',
            'ship_date',
            'product',
            'quantity',
            'price',
        ],
        index_col = [
            'salesperson',
            'customer',
            'invoice_date',
            'ship_date',
        ],
        parse_dates = [
            'invoice_date',
            'ship_date',
        ],
    )
except Exception as e:
    print(e)

try:
    print(df)
    print(df.loc[(
        'Alex',                    # salesperson
        'ZZYZX',                   # customer
        '2011-03-02 00:00:00',     # invoice_date
        '2011-03-05 00:00:00',     # ship_date
    )])
except Exception as e:
    print(e)

Upvotes: 1

Views: 718

Answers (1)

Rutger Kassies
Rutger Kassies

Reputation: 64463

It seems to work fine, im getting a proper df. Although i would try avoiding the empty entries in every list.

If you use parse_dates you should also access those columns with a proper datetime object:

df.loc[('Alex','ZZYZX',pd.datetime(2011,3,2),pd.datetime(2011,3,5))]

product        A
quantity      10
price       11.4
Name: (Alex, ZZYZX, 2011-03-02 00:00:00, 2011-03-05 00:00:00), dtype: object

Upvotes: 1

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