Add capability to created wanted variables list with an explicit list of paths

icepyx/core/variables.py

@@ -429,7 +429,14 @@ def _iter_paths(self, sum_varlist, req_vars, vgrp, beam_list, keyword_list):
         return req_vars
 
     # DevGoal: we can ultimately add an "interactive" trigger that will open the not-yet-made widget. Otherwise, it will use the var_list passed by the user/defaults
-    def append(self, defaults=False, var_list=None, beam_list=None, keyword_list=None):
+    def append(
+        self,
+        defaults=False,
+        var_list=None,
+        beam_list=None,
+        keyword_list=None,
+        path_list=None,
+    ):
         """
         Add to the list of desired variables using user specified beams and variable list.
         A pregenerated default variable list can be used by setting defaults to True.
@@ -457,6 +464,9 @@ def append(self, defaults=False, var_list=None, beam_list=None, keyword_list=Non
             the product that include that keyword in their path. A list of availble keywords can be obtained by
             entering `keyword_list=['']` into the function.
 
+        path_list : list of strings, default None
+            A list of variable path names given as a the full path from the H5 root path.
+
         Notes
         -----
         See also the `IS2_data_access2-subsetting
@@ -482,25 +492,59 @@ def append(self, defaults=False, var_list=None, beam_list=None, keyword_list=Non
         To add all variables and paths in ancillary_data
 
         >>> reg_a.order_vars.append(keyword_list=['ancillary_data']) # doctest: +SKIP
+
+        To add variables as a list of explicit paths
+
+        >>> path_list = ['gt1l/heights/delta_time',
+                         'gt1l/heights/dist_ph_across',
+                         'gt1l/heights/dist_ph_along',
+                         'gt1l/heights/h_ph',
+                         'gt1l/heights/lat_ph',
+                         'gt1l/heights/lon_ph']
+        >>> region_a.order_vars.append(path_list=path_list)  # doctest: +SKIP
+
         """
 
-        assert not (
-            defaults == False
-            and var_list == None
-            and beam_list == None
-            and keyword_list == None
-        ), "You must enter parameters to add to a variable subset list. If you do not want to subset by variable, ensure your is2.subsetparams dictionary does not contain the key 'Coverage'."
+        # Check that at least one allowable combination of keywords are set
+        if (
+            not defaults
+            and not (var_list or beam_list or keyword_list)
+            and not path_list
+        ):
+            raise ValueError(
+                "Either default or path_list, or at least one of var_list, "
+                "beam_list or keyword_list must be set\n"
+                "If you do not want to subset by variable, "
+                "ensure your is2.subsetparams dictionary does "
+                "not contain the key 'Coverage'."
+            )
+
+        # Check that only path_list, or only var_list, beam_list or keyword_list
+        # are set.
+        if (var_list or beam_list or keyword_list) and path_list:
+            raise ValueError(
+                "path_list cannot be set if var_list or "
+                "beam_list or keyword_list are set"
+            )
 
         final_vars = {}
 
+        if path_list:
+            _, (beams, keywords, variables) = self.parse_var_list(
+                path_list, tiered_vars=True
+            )
+            var_list = list(set(variables))
+            beam_list = list(set(beams))
+            keyword_list = list(set(keywords))
+
         vgrp, allpaths = self.avail(options=True, internal=True)
         self._check_valid_lists(vgrp, allpaths, var_list, beam_list, keyword_list)
 
-        # Instantiate self.wanted to an empty dictionary if it doesn't exist
+        # Instantiate self.wanted to an empty dictionaryto an  if it doesn't exist
         if not hasattr(self, "wanted") or self.wanted == None:
             self.wanted = {}
 
-            # DEVGOAL: add a secondary var list to include uncertainty/error information for lower level data if specific data variables have been specified...
+        # DEVGOAL: add a secondary var list to include uncertainty/error information for lower level data if specific data variables have been specified...
 
         # generate a list of variable names to include, depending on user input
         sum_varlist = self._get_sum_varlist(var_list, vgrp.keys(), defaults)