Empty printer file causes crash

[mikelarelarra]

Some types may create automatic printer files (which may be empty). If that's the case, the post-processing crashes when reading.

pandas.errors.EmptyDataError: No columns to parse from file

[ahobeost]

After some debugging, this does not seem to crash the reading step.
Instead, the problem seems to be with a file created using type 46 (printegrator) for timesteps.
For certain columns, it is complaining about NaN values and then crashes.

When this happens, one could use type 25 instead.
However, the processing uses _step to recognize the type 46 version.
So when switching to type 25, it is best to remove this.
A better solution will be needed in the future.

[ahobeost]

When this happens, one could use type 25 instead. However, the processing uses _step to recognize the type 46 version. So when switching to type 25, it is best to remove this. A better solution will be needed in the future.

Ending a file name with "_step.prt" now works for both type 25 and type 46 for the common settings in pytrnsys #126.
It is unclear if this fixes this issue, as we do not have an example yet.