How do I change or access pandas MultiIndex column headers?

Question

I have the following Pandas DataFrame, but am having trouble updating a column header value, or easily accessing the header values (for example, for plotting a time at the (

Answer 1

You access MultiIndex via tuples. For example:

df.loc[:, ('id0', 66, 110)]

However, you may want to access via lon/lat without specifying id or maybe you'll have multiple ids. In that case, you can do 2 things.

First, use pd.IndexSlice which allows for useful MultiIndex slicing:

df.loc[:, pd.IndexSlice[:, 66, 110]]

Second:

df.stack(0).loc[:, (66, 110)].dropna().unstack()

Which is messier, but might be useful.

Finally, the last thing you mentioned. For a specific row with lon/lat.

df.loc[2014, pd.IndexSlice[:, 66, 110]]