Added .invoke() support

filterator/commands.py

@@ -1,5 +1,5 @@
 from itertools import imap
-from operator import attrgetter
+from operator import attrgetter, methodcaller
 
 from errors import MultipleValuesReturned
 from constraints import ConstraintsFactory, CallableConstraint
@@ -14,6 +14,7 @@
     'CountCommand',
     'SumCommand',
     'ExistsCommand',
+    'InvokeCommand',
 )
 
 
@@ -178,6 +179,18 @@ def execute(self):
             return self.context.filter(*self.args, **self.kwargs).get()
 
 
+class InvokeCommand(BaseCommand):
+    def __init__(self, context, iterable, method_name, *args, **kwargs):
+        self.method_name = method_name
+        super(InvokeCommand, self).__init__(context, iterable, *args, **kwargs)
+
+    def execute(self):
+        return map(
+            methodcaller(self.method_name, *self.args, **self.kwargs),
+            self.iterable
+        )
+
+
 class CountCommand(BaseCommand):
     def execute(self):
         return len(self.iterable)

filterator/filterator.py

@@ -23,6 +23,9 @@ def order_by(self, *keys):
     def get(self, *callables, **constrains):
         return self.__execute_command(GetCommand, *callables, **constrains)
 
+    def invoke(self, method_name, *args, **kwargs):
+        return self.__execute_command(InvokeCommand, method_name, *args, **kwargs)
+
     def count(self):
         return self.__execute_command(CountCommand)
 

filterator/tests.py

@@ -8,7 +8,15 @@
 
 class Person(namedtuple('Person', 'name age sex children vehicle')):
     def is_car_driver(self):
-        return self.vehicle and self.vehicle.type == 'car'
+        return self.vehicle is not None and self.vehicle.type == 'car'
+
+    def is_age_dividable_by(self, num):
+        return self.age % num == 0
+
+    def get_vehicle_manufacturer(self, default=None):
+        if self.is_car_driver():
+            return self.vehicle.manufacturer
+        return default
 
 
 Vehicle = namedtuple('Vehicle', 'type manufacturer')
@@ -231,5 +239,25 @@ def test_order_by_method(self):
         self.assertEqual([self.dog, self.human, self.spider], self.creatures.order_by('get_name'))
 
 
+class TestInvoke(FilteratorTestCase):
+    def test_no_arguments(self):
+        self.assertEqual(
+            [False, False, False, True],
+            self.people.invoke('is_car_driver')
+        )
+
+    def test_args(self):
+        self.assertEqual(
+            [True, False, False, False],
+            self.people.invoke('is_age_dividable_by', 2)
+        )
+
+    def test_kwargs(self):
+        self.assertEqual(
+            ['foo', 'foo', 'foo', 'ford'],
+            self.people.invoke('get_vehicle_manufacturer', default='foo')
+        )
+
+
 if __name__ == '__main__':
     unittest2.main()