GH AllenInstitute#533 - Check for autobias_v in sweep_metadata keys

First check that autobias_v is present in sweep_metadata.keys() before assigning value in
Sweep(), set to None if not present. Also added autobias_v as None in
test_get_sweep_metadata from test_mies_nwb_data.py so that expected
result and obtained result match.

ipfx/dataset/ephys_data_set.py

@@ -228,6 +228,10 @@ def sweep(self, sweep_number: int) -> Sweep:
 
         sweep_data = self.get_sweep_data(sweep_number)
         sweep_metadata = self._data.get_sweep_metadata(sweep_number)
+        if "autobias_v" in sweep_metadata.keys():
+            autobias_v = sweep_metadata["autobias_v"]
+        else:
+            autobias_v = None
 
         time = np.arange(
             len(sweep_data["stimulus"])
@@ -248,8 +252,8 @@ def sweep(self, sweep_number: int) -> Sweep:
                 sampling_rate=sweep_data["sampling_rate"],
                 sweep_number=sweep_number,
                 clamp_mode=sweep_metadata["clamp_mode"],
-                autobias_v = sweep_metadata["autobias_v"],
                 epochs=sweep_data.get("epochs", None),
+                autobias_v = autobias_v
             )
 
         except Exception:

tests/dataset/test_mies_nwb_data.py

@@ -58,6 +58,7 @@ def test_get_sweep_metadata(mies_nwb_data):
         'stimulus_code_ext': 'STIMULUS_CODE[1]',
         'clamp_mode': 'CurrentClamp',
         'stimulus_name': 'expected name',
+        'autobias_v': None
     }
 
     obtained = mies_nwb_data.get_sweep_metadata(sweep_number=4)