Pandas extract dataframe time series

Question

In the following dataframe, datetime column is the index, and I want to extract values from 2015 to 2020.

df[(df.index>=2015) & (df.index<=2020)]

However, when I use the command above, it only extracts values ranging from Jan 1st 2015 to Jan 1st 2020. I would like it to extract all values for 2020. Any suggestions?

datetime    NMN
3/21/2012   0.5221
3/22/2012   0.5089
3/23/2012   0.4782
3/24/2012   0.4587
3/25/2012   0.5012
3/26/2012   0.5468
3/27/2012   0.5949
3/28/2012   0.6279
3/29/2012   0.682
...
12/21/2022  0.6377
12/22/2022  0.5864
12/23/2022  0.559
12/24/2022  0.5429
12/25/2022  0.5293
12/26/2022  0.5394
12/27/2022  0.6248
12/28/2022  0.6565
12/29/2022  0.6799
12/30/2022  0.5756
12/31/2022  0.5475

Answer 1

specify the end of the year, use quotations, and also use ix to select index values:

df.ix['2012':'2022-12-31']

               NMN
datetime          
2012-03-21  0.5221
2012-03-22  0.5089
2012-03-23  0.4782
2012-03-24  0.4587
2012-03-25  0.5012
2012-03-26  0.5468
2012-03-27  0.5949
2012-03-28  0.6279
2012-03-29  0.6820
2022-12-21  0.6377
2022-12-22  0.5864
2022-12-23  0.5590
2022-12-24  0.5429
2022-12-25  0.5293
2022-12-26  0.5394
2022-12-27  0.6248
2022-12-28  0.6565
2022-12-29  0.6799
2022-12-30  0.5756
2022-12-31  0.5475

The following also works just fine, producing the same output as above:

df.ix['2012':'2022']