Address code review nitpicks: improve code clarity and efficiency

Co-authored-by: tanghaibao <[email protected]>

Author: Copilot

docs/descendants_with_relationships_example.py

@@ -50,17 +50,19 @@
 print("-" * 70)
 
 # Get descendants for ALL GO terms in the DAG
+# Extract godag.values() once for efficiency
+goterms = godag.values()
 
 # Option A: is_a only
-go2descendants_isa = get_go2descendants(godag.values(), relationships=None)
+go2descendants_isa = get_go2descendants(goterms, relationships=None)
 print(f"   is_a only:              {sorted(go2descendants_isa.get(GO_ID, set()))}")
 
 # Option B: is_a + ALL relationships
-go2descendants_all = get_go2descendants(godag.values(), relationships=True)
+go2descendants_all = get_go2descendants(goterms, relationships=True)
 print(f"   is_a + all relations:   {sorted(go2descendants_all.get(GO_ID, set()))}")
 
 # Option C: is_a + SELECTED relationships (e.g., only part_of)
-go2descendants_partof = get_go2descendants(godag.values(), relationships={'part_of'})
+go2descendants_partof = get_go2descendants(goterms, relationships={'part_of'})
 print(f"   is_a + part_of only:    {sorted(go2descendants_partof.get(GO_ID, set()))}")
 
 # ============================================================================

notebooks/children_and_descendants.ipynb

@@ -89,9 +89,10 @@
       "source": [
         "from goatools.godag.go_tasks import get_go2children\n",
         "\n",
-        "optional_relationships = {'part_of'}\n",
+        "optional_relationships = {\"part_of\"}\n",
+        "# Note: GODag inherits from dict, so we pass godag directly\n",
         "go2children_partof = get_go2children(godag, optional_relationships)\n",
-        "print('{GO} children (is_a + part_of): {C}'.format(\n",
+        "print(\"{GO} children (is_a + part_of): {C}\".format(\n",
         "    GO=GO_ID,\n",
         "    C=go2children_partof.get(GO_ID, set())))"
       ]