pandas HDFStore - how to reopen?

Question

I created a file by using:

store = pd.HDFStore(\'/home/.../data.h5\')

and stored some tables using:

store[\'firstSet\'] = df1
s         


        

Answer 1

I had the same problem and finally fixed it by installing the pytables module (next to the pandas modules which I was using):

conda install pytables

which got me numexpr-2.4.3 and pytables-3.2.0

After that it worked. I am using pandas 0.16.2 under python 2.7.9

Answer 2

You could try doing instead:

store = pd.io.pytables.HDFStore('/home/.../data.h5')
df1 = store['firstSet']

or use the read method directly:

df1 = pd.read_hdf('/home/.../data.h5', 'firstSet')

Either way, you should have pandas 0.12.0 or higher...

Answer 3

In my hands, following approach works best:

df = pd.DataFrame(...)

"write"
with pd.HDFStore('test.h5',  mode='w') as store:
    store.append('df', df, data_columns= df.columns, format='table')

"read"
with pd.HDFStore('test.h5',  mode='r') as newstore:
    df_restored = newstore.select('df')