allow specifying scope variables as keyword arguments

Author: Mike Dirolf

pymongo/code.py

@@ -20,30 +20,44 @@ class Code(str):
  """JavaScript code to be evaluated by MongoDB.
 
  Raises :class:`TypeError` if `code` is not an instance of
- :class:`basestring` or `scope` is not an instance of
+ :class:`basestring` or `scope` is not ``None`` or an instance of
  :class:`dict`.
 
+ Scope variables can be set by passing a dictionary as the `scope`
+ argument or by using keyword arguments. If a variable is set as a
+ keyword argument it will override any setting for that variable in
+ the `scope` dictionary.
+
  :Parameters:
  - `code`: string containing JavaScript code to be evaluated
  - `scope` (optional): dictionary representing the scope in which
  `code` should be evaluated - a mapping from identifiers (as
  strings) to values
+ - `**kwargs` (optional): scope variables can also be passed as
+ keyword arguments
+
+ .. versionadded:: 1.8.1+
+ Ability to pass scope values using keyword arguments.
  """
 
- def __new__(cls, code, scope=None):
+ def __new__(cls, code, scope=None, **kwargs):
  if not isinstance(code, basestring):
  raise TypeError("code must be an instance of basestring")
 
- if scope is None:
- try:
- scope = code.scope
- except AttributeError:
- scope = {}
- if not isinstance(scope, dict):
- raise TypeError("scope must be an instance of dict")
-
  self = str.__new__(cls, code)
- self.__scope = scope
+
+ try:
+ self.__scope = code.scope
+ except AttributeError:
+ self.__scope = {}
+
+ if scope is not None:
+ if not isinstance(scope, dict):
+ raise TypeError("scope must be an instance of dict")
+ self.__scope.update(scope)
+
+ self.__scope.update(kwargs)
+
  return self
 
  @property

test/test_code.py

@@ -84,6 +84,12 @@ def test_scope_preserved(self):
  self.assertNotEqual(a, Code(b))
  self.assertNotEqual(b, Code(a))
 
+ def test_scope_kwargs(self):
+ self.assertEqual({"a": 1}, Code("", a=1).scope)
+ self.assertEqual({"a": 1}, Code("", {"a": 2}, a=1).scope)
+ self.assertEqual({"a": 1, "b": 2, "c": 3},
+ Code("", {"b": 2}, a=1, c=3).scope)
+
 
 if __name__ == "__main__":
  unittest.main()