Fix bug that occurred when partialed module was passed.

skorch/net.py

@@ -381,7 +381,7 @@ def initialize_module(self):
         """
         kwargs = self._get_params_for('module')
         module = self.module
-        is_initialized = not isinstance(module, type)
+        is_initialized = isinstance(module, torch.nn.Module)
 
         if kwargs or not is_initialized:
             if is_initialized:

skorch/tests/test_net.py

@@ -382,6 +382,11 @@ def test_module_params_in_init(self, net_cls, module_cls, data):
         assert net.module_.dense1.in_features == 20
         assert net.module_.nonlin is F.tanh
 
+    def test_module_initialized_with_partial_module(self, net_cls, module_cls):
+        net = net_cls(partial(module_cls, num_units=123))
+        net.initialize()
+        assert net.module_.dense0.out_features == 123
+
     def test_criterion_init_with_params(self, net_cls, module_cls):
         mock = Mock()
         net = net_cls(module_cls, criterion=mock, criterion__spam='eggs')