For certain chirp sweeps, this was failing due to an empty epoch before the real one, like {'Duration': '0', 'Epoch': '0', 'Sweep': '0', 'Type': 'Sin Wave'}.
This raised an exception in the epoch processing and thus the item variable was never assigned to.
For certain chirp sweeps, this was failing due to an empty epoch before the real one, like {'Duration': '0', 'Epoch': '0', 'Sweep': '0', 'Type': 'Sin Wave'}. This raised an exception in the epoch processing and thus the item variable was never assigned to.