Pandas slicing along multiindex and separate indices

Question

I\'ve started using Pandas for some large Datasets and mostly it works really well. There are some questions I have regarding the indices though

1. I have a MultiI

Answer 1

Edit: This answer for pandas versions lower than 0.10.0 only:

Okay @hayden had the right idea to start with:

An index has the method get_level_values() which returns, however, an array (in pandas versions < 0.10.0). The isin() method doesn't exist for arrays but this works:

from pandas import lib
lib.ismember(df.index.get_level_values('a'), set([5, 7, 10, 13])

That only answers question 1 - but I'll give an update if I crack 2, 3 (half done with @hayden's help)

Answer 2

For the first part, you can use boolean indexing using get_level_values:

df[df.index.get_level_values('a').isin([5, 7, 10, 13])]

For the second two, you can inspect the MultiIndex object by calling:

df.index

(and this can be inspected/sliced.)