Add optional parameter for pymongo.database.collection_names to ignore system collections

Author: Park Hyunwoo

pymongo/database.py

@@ -397,14 +397,19 @@ def command(self, command, value=1,
 
  return result
 
- def collection_names(self):
+ def collection_names(self, include_system_collections=True):
  """Get a list of all the collection names in this database.
+
+ :Parameters:
+ - `include_system_collections` (optional): if ``False`` list
+ will not include system collections (e.g ``system.indexes``)
  """
  results = self["system.namespaces"].find(_must_use_master=True)
  names = [r["name"] for r in results]
  names = [n[len(self.__name) + 1:] for n in names
- if n.startswith(self.__name + ".")]
- names = [n for n in names if "$" not in n]
+ if n.startswith(self.__name + ".") and "$" not in n]
+ if not include_system_collections:
+ names = [n for n in names if not n.startswith("system.")]
  return names
 
  def drop_collection(self, name_or_collection):

test/test_database.py

@@ -114,6 +114,10 @@ def test_collection_names(self):
  for coll in colls:
  self.assertTrue("$" not in coll)
 
+ colls_without_systems = db.collection_names(False)
+ for coll in colls_without_systems:
+ self.assertTrue(not coll.startswith("system."))
+
  def test_drop_collection(self):
  db = Database(self.client, "pymongo_test")