CODEWITHSUNDEEP
python-3.xpandastime-series
René
René

Reputation: 4827

pandas timeseries select single date

Selecting a single date from a timeserie gives a KeyError.

Setup:

import pandas as pd
import numpy as np
ts = pd.DataFrame({'date': pd.date_range(start = '1/1/2017', periods = 5),
                   'observations': np.random.choice(range(0, 100), 5, replace = True)}).set_index('date')

Dataframe:

           observations
date                    
2017-01-01            58
2017-01-02            88
2017-01-03            53
2017-01-04             4
2017-01-05            26

How do I select the number of observations for a single date?

ts['2017-01-01']

Returns: KeyError: '2017-01-01'

But...

ts['2017-01-01':'2017-01-01']

...seems to work just fine.

Any suggestions how to select/subset with a single date?

Upvotes: 1

Views: 91

Answers (1)

Ben.T
Ben.T

Reputation: 29635

As @scnerd pointed out, when you do ts['2017-01-01'] it tries to find '2017-01-01' as a column's name of the dataframe ts, which gives you an KeyError as none of the columns in ts has this name

In order to look for an index' name, as in your example 'date' is set as index, you need to use loc method such as ts.loc['2017-01-01'] and you will get:

observations    54
Name: 2017-01-01 00:00:00, dtype: int32

Upvotes: 2

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