get the dtype of a pandas multiindex

Question

How can I find the dtype of a MultiIndex in pandas without printing out all the values (this happens if you type df.index, for example). I just want to know the names of the indices and their types.

Ex:

df = pd.DataFrame({"a": np.arange(100000), "b": np.arange(100000)[::-1]}, index=pd.MultiIndex.from_arrays([np.arange(100000), np.arange(100000)[::-1]], names=["i1", "i2"]))

doing:

df.index

will take some time to actually print, for a large df that's too long.

Answer 1

Use get_level_values:

df.index.get_level_values(0).dtype
dtype('int64')

and

df.index.get_level_values(1).dtype
dtype('int64')

For names use:

df.index.names
FrozenList(['i1', 'i2'])

Answer 2

pandas >= 1.3 [est]

Coming soon to a distro near you, you MultiIndex.dtypes will soon be available:

df.index.dtypes

i1    int64
i2    int64
dtype: object 

---

For older versions, if your index is not too large, you can first convert to a frame using to_frame, then query the dtypes:

df.index.to_frame().dtypes

i1    int64
i2    int64
dtype: object