Naturally, you will feel more comfortable storing your data in the HDF5 format if you understand how to get it back out. Imagine you have a file with the following hierarchy:
mydata.h5
/entry_1/measurement/scalar_data/motor_1
motor_2
ion_chamber_1
/MCA/counts
deadtime
and you want to export channels 500-550 of the first three MCA spectra to an ASCII text file. You can do so with the following simple python code, which can be run as a script or in an interactive session:
from phynx import File
import numpy
f = File('mydata.h5')
mca_spectra = f['/entry_1/measurement/MCA/counts'][:3, 500:551]
numpy.savetxt('mca_spectra.txt', mca_spectra, fmt='%g')