closing session crashes when frames are dropped

[iverissimo]

Hey,

I'm designing a stimuli that has fairly fast flickering, and I want the trial to stop upon a keypress.

I noticed that the code would crash when defining and saving the global_log with the message:

File "/Users/verissimo/anaconda3/envs/i36/lib/python3.6/site-packages/exptools2-0.1.dev0-py3.6.egg/exptools2/core/session.py", line 251, in close
    self.global_log.loc[nonresp_idx, 'nr_frames'] = nr_frames.astype(int)
ValueError: cannot convert float NaN to integer

I think it's because of frames dropping throughout the trial. I solved it by replacing this line

exptools2/exptools2/core/session.py

Line 251 in b41407a

self.global_log.loc[nonresp_idx, 'nr_frames'] = nr_frames.astype(int)

with:
self.global_log.loc[nonresp_idx, 'nr_frames'] = nr_frames.astype(np.float).astype('Int32')

[lukassnoek]

Sounds good. Maybe easiest to just push to master? (@tknapen )