Selection with a MultiIndex – Multiple levels

Things would not be that interesting if you could only select from the first level of a pd.MultiIndex. Fortunately, pd.DataFrame.loc will scale out to more than just the first level through the creative use of tuple arguments.

How to do it

Let’s recreate the pd.Series from the previous section:

index = pd.MultiIndex.from_tuples([
    ("John", "Smith"),
    ("John", "Doe"),
    ("Jane", "Doe"),
    ("Stephen", "Smith"),
], names=["first_name", "last_name"])
ser = pd.Series(range(4), index=index)
ser

first_name  last_name
John        Smith        0
            Doe          1
Jane        Doe          2
Stephen     Smith        3
dtype: int64

To select all records where the first index level uses the label "Jane" and the second uses "Doe", pass the following tuple:

ser.loc[("Jane...