import pandas as pd
import pyarrow as pa
import pyarrow.feather as feather
pd.__version__
# '0.23.4'
pa.__version__
# '0.10.0'
df = pd.DataFrame(dict(a=[1, 2], b=['foo', pd.NaT], c=[3.14, -float('inf')], d=['baz', 'baz'])).set_index(['a', 'b'])
df.d = df.d.astype('category')
df.columns = pd.MultiIndex.from_product([[42], ['foo', 'bar']])
df.index
# MultiIndex(levels=[[1, 2], ['foo']],
# labels=[[0, 1], [0, -1]],
# names=['a', 'b'])
df.columns
# MultiIndex(levels=[[42], ['bar', 'foo']],
# labels=[[0, 0], [1, 0]])
feather.write_feather(df, PATH)
read_df = feather.read_feather(PATH)
read_df.index
# RangeIndex(start=0, stop=2, step=1)
read_df.columns
# Index(['('42', 'foo')', '('42', 'bar')'], dtype='object')
