One reason to use binary formats like HDF5 is to avoid precision loss when storing floating-point values. I started using HDF5 once exactly for this reason and it was overkill. HDFView requires Java installed and HDF library with single implementation and complex API is a problem too.<p>For simple uses I now use &#x27;%a&#x27; printf specifier. It is specifically designed to avoid losing a single bit of informaiton. And you can easily read floats stored this way in numpy by using genfromtxt with optional converters= argument and builtin float.fromhex function.