Есть ли способ заставить панд записать пустой DataFrame в файл HDF?
import pandas as pd
df = pd.DataFrame(columns=['x','y'])
df.to_hdf('temp.h5', 'xxx')
df2 = pd.read_hdf('temp.h5', 'xxx')
Выход:
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File ".../Python-3.6.3/lib/python3.6/site-packages/pandas/io/pytables.py", line 389, in read_hdf
return store.select(key, auto_close=auto_close, **kwargs)
File ".../Python-3.6.3/lib/python3.6/site-packages/pandas/io/pytables.py", line 740, in select
return it.get_result()
File ".../Python-3.6.3/lib/python3.6/site-packages/pandas/io/pytables.py", line 1518, in get_result
results = self.func(self.start, self.stop, where)
File ".../Python-3.6.3/lib/python3.6/site-packages/pandas/io/pytables.py", line 733, in func
columns=columns)
File ".../Python-3.6.3/lib/python3.6/site-packages/pandas/io/pytables.py", line 2986, in read
idx=i), start=_start, stop=_stop)
File ".../Python-3.6.3/lib/python3.6/site-packages/pandas/io/pytables.py", line 2575, in read_index
_, index = self.read_index_node(getattr(self.group, key), **kwargs)
File ".../Python-3.6.3/lib/python3.6/site-packages/pandas/io/pytables.py", line 2676, in read_index_node
data = node[start:stop]
File ".../Python-3.6.3/lib/python3.6/site-packages/tables/vlarray.py", line 675, in __getitem__
return self.read(start, stop, step)
File ".../Python-3.6.3/lib/python3.6/site-packages/tables/vlarray.py", line 811, in read
listarr = self._read_array(start, stop, step)
File "tables/hdf5extension.pyx", line 2106, in tables.hdf5extension.VLArray._read_array (tables/hdf5extension.c:24649)
ValueError: cannot set WRITEABLE flag to True of this array
Запись с format='table'
:
import pandas as pd
df = pd.DataFrame(columns=['x','y'])
df.to_hdf('temp.h5', 'xxx', format='table')
df2 = pd.read_hdf('temp.h5', 'xxx')
Выход:
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File ".../Python-3.6.3/lib/python3.6/site-packages/pandas/io/pytables.py", line 389, in read_hdf
return store.select(key, auto_close=auto_close, **kwargs)
File ".../Python-3.6.3/lib/python3.6/site-packages/pandas/io/pytables.py", line 722, in select
raise KeyError('No object named {key} in the file'.format(key=key))
KeyError: 'No object named xxx in the file'
Версия для панд: 0.24.2
Спасибо за помощь!