Fix NetCDF generation when one of the input files is missing

aosstower/level_b1/nc.py

@@ -302,8 +302,16 @@ def summary_over_interval(frame, interval_width):
 
 
 def _get_data(input_files):
+    bad_files = 0
     for filename in input_files:
-        yield from parser.read_frames(filename)
+        try:
+            yield from parser.read_frames(filename)
+        except FileNotFoundError:
+            LOG.warning("Input data file was not found: {}".format(filename))
+            bad_files += 1
+            continue
+    if bad_files == len(input_files):
+        raise ValueError("No valid input data files found")
 
 
 def get_data(input_files):