check errors raised by empty query object from bounding box split in …

…openaltimetry visualization (#220)

Co-authored-by: Jessica <JessicaS11@users.noreply.github.com>

icepyx/core/visualization.py

@@ -238,14 +238,17 @@ def query_icesat2_filelist(self) -> tuple:
 
  for bbox_i in bbox_list:
 
- region = ipx.Query(
- self.product,
- bbox_i,
- self.date_range,
- cycles=self.cycles,
- tracks=self.tracks,
- )
- icesat2_files = region.avail_granules(ids=True)[0]
+ try:
+ region = ipx.Query(
+ self.product,
+ bbox_i,
+ self.date_range,
+ cycles=self.cycles,
+ tracks=self.tracks,
+ )
+ icesat2_files = region.avail_granules(ids=True)[0]
+ except (AttributeError, AssertionError):
+ continue
 
  if not icesat2_files:
  continue
@@ -408,6 +411,8 @@ def parallel_request_OA(self) -> da.array:
  # generate parameter lists for OA requesting
  OA_para_list = self.generate_OA_parameters()
 
+ assert OA_para_list, "Your search returned no results; try different search parameters"
+
  url_number = len(OA_para_list)
 
  if url_number > 200: