Patch to read_velocity_cells to make return types consistent and to r…

…aise errors instead of returning None

pyVlsv/vlsvreader.py

@@ -3017,8 +3017,8 @@ def read_velocity_cells(self, cellid, pop="proton"):
  self.__set_cell_offset_and_blocks(pop) 
  # Check that cells has vspace
  if not cellid in self.__fileindex_for_cellid_blocks[pop]:
- print("Cell does not have velocity distribution")
- return []
+ warnings.warn("Cell(s) does not have velocity distribution")
+ return {}
  # Navigate to the correct position:
  offset = self.__fileindex_for_cellid_blocks[pop][cellid][0]
  num_of_blocks = self.__fileindex_for_cellid_blocks[pop][cellid][1]
@@ -3030,8 +3030,8 @@ def read_velocity_cells(self, cellid, pop="proton"):
  try:
  cells_with_blocks_index = self.__order_for_cellid_blocks[pop][cellid]
  except:
- print("Cell does not have velocity distribution")
- return []
+ warnings.warn("Cell(s) does not have velocity distribution")
+ return {}
  # Navigate to the correct position:
  offset = self.__blocks_per_cell_offsets[pop][cells_with_blocks_index]
  num_of_blocks = self.__blocks_per_cell[pop][cells_with_blocks_index]
@@ -3074,8 +3074,7 @@ def read_velocity_cells(self, cellid, pop="proton"):
  elif datatype == "uint" and element_size == 8:
  data_block_ids = np.fromfile(fptr, dtype = np.uint64, count = vector_size*num_of_blocks)
  else:
- print("Error! Bad data type in blocks!")
- return
+ raise TypeError("Error! Bad data type in blocks! datatype found was "+datatype)
 
  if (pop=="avgs") and (child.tag == "BLOCKIDS"): # Old avgs files did not have the name set for BLOCKIDS
  vector_size = ast.literal_eval(child.attrib["vectorsize"])
@@ -3091,16 +3090,15 @@ def read_velocity_cells(self, cellid, pop="proton"):
  elif datatype == "uint" and element_size == 8:
  data_block_ids = np.fromfile(fptr, dtype = np.uint64, count = vector_size*num_of_blocks)
  else:
- print("Error! Bad data type in blocks!")
- return
+ raise TypeError("Error! Bad data type in blocks! datatype found was "+datatype)
 
  data_block_ids = data_block_ids.reshape(num_of_blocks, vector_size)
 
  fptr.close()
 
  # Check to make sure the sizes match (just some extra debugging)
  if len(data_avgs) != len(data_block_ids):
- print("BAD DATA SIZES")
+ raise ValueError("BAD DATA SIZES")
  # Make a dictionary (hash map) out of velocity cell ids and avgs:
  velocity_cells = {}
  array_size = len(data_avgs)