Missing optional dependency 'tables'. In pandas to_hdf

Question

• following code is giving me error.

import pandas as pd
df = pd.DataFrame({'a' : [1,2,3]})
df.to_hdf('temp.h5', key='df', mode='w')

• This is giving me error.

  Missing optional dependency 'tables'. Use pip or conda to install tables.

• I already tried ImportError HDFStore requires PyTables No module named tables. Still the same error.

• I am getting the same error when reading hdf file. And tables are already installed for my python.

Some version info.

• python 3.7.4
• pandas 0.25.2
• windows10

PS: You can reproduce this in repl https://repl.it/.

Update:

• I tried runnig following.

import tables

and got this error:

ImportError: Could not load any of ['hdf5.dll', 'hdf5dll.dll'], please ensure that it can be found in the system path.

• It looks like pandas is not giving accurate message for this. Its just saying missing dependency when its actually present.

• If anyone knows how to resolve this. That will help.

Answer 1

For conda users:

conda install pytables

Answer 2

I got it to work by using

conda install snappy

Answer 3

• The issue was with tables.
• When i was installing tables using pip into local user directory using following command it's not working.

pip install --user tables

• Running import tables will result in this error.

  ImportError: Could not load any of ['hdf5.dll', 'hdf5dll.dll'], please ensure that it can be found in the system path

• The solution that worked for me is to uninstall tables. And install it into python's directory. (or where your python is installed). without --user option. You may require admin/root access for this depending upon location of your python.

• For me my python path was C:\Program Files\Python37-64\python.exe and installing under c:\program files\python37-64\lib\site-packages\ worked for me.
• Hope this helps. I don't know why installing in user directory is not working for tables. If anyone can find the reason for that please post here.