Block Structure API: Replace has_block with __contains__

openedx/core/lib/block_structure/block_structure.py

@@ -79,6 +79,7 @@ class BlockStructure(object):
         Returns the parents of the block identified by the given
         usage_key.
 
+
         Arguments:
             usage_key - The usage key of the block whose parents
                 are to be returned.
@@ -86,7 +87,7 @@ class BlockStructure(object):
         Returns:
             [UsageKey] - A list of usage keys of the block's parents.
         """
-        return self._block_relations[usage_key].parents if self.has_block(usage_key) else []
+        return self._block_relations[usage_key].parents if usage_key in self else []
 
     def get_children(self, usage_key):
         """
@@ -100,7 +101,7 @@ class BlockStructure(object):
         Returns:
             [UsageKey] - A list of usage keys of the block's children.
         """
-        return self._block_relations[usage_key].children if self.has_block(usage_key) else []
+        return self._block_relations[usage_key].children if usage_key in self else []
 
     def set_root_block(self, usage_key):
         """
@@ -117,7 +118,7 @@ class BlockStructure(object):
         self.root_block_usage_key = usage_key
         self._block_relations[usage_key].parents = []
 
-    def has_block(self, usage_key):
+    def __contains__(self, usage_key):
         """
         Returns whether a block with the given usage_key is in this
         block structure.

openedx/core/lib/block_structure/manager.py

@@ -57,7 +57,7 @@ class BlockStructureManager(object):
             # Override the root_block_usage_key so traversals start at the
             # requested location.  The rest of the structure will be pruned
             # as part of the transformation.
-            if not block_structure.has_block(starting_block_usage_key):
+            if starting_block_usage_key not in block_structure:
                 raise UsageKeyNotInBlockStructure(
                     "The requested usage_key '{0}' is not found in the block_structure with root '{1}'",
                     unicode(starting_block_usage_key),

openedx/core/lib/block_structure/tests/helpers.py

@@ -219,7 +219,7 @@ class ChildrenMapTestMixin(object):
         for block_key, children in enumerate(children_map):
             # Verify presence
             self.assertEquals(
-                block_structure.has_block(block_key),
+                block_key in block_structure,
                 block_key not in missing_blocks,
                 'Expected presence in block_structure for block_key {} to match absence in missing_blocks.'.format(
                     unicode(block_key)

openedx/core/lib/block_structure/tests/test_block_structure.py

@@ -37,10 +37,10 @@ class TestBlockStructure(TestCase, ChildrenMapTestMixin):
         for child, parents in enumerate(self.get_parents_map(children_map)):
             self.assertSetEqual(set(block_structure.get_parents(child)), set(parents))
 
-        # has_block
+        # __contains__
         for node in range(len(children_map)):
-            self.assertTrue(block_structure.has_block(node))
-        self.assertFalse(block_structure.has_block(len(children_map) + 1))
+            self.assertIn(node, block_structure)
+        self.assertNotIn(len(children_map) + 1, block_structure)
 
 
 @ddt.ddt