@bodokaiser, are you sure the model.modules()  nn.Conv2d instance has weights attribute?
Cause I tried to access the weights using your example and it returns
  self.weights = m.weights#.data
  File "/home/user/anaconda2/envs/py27/lib/python2.7/site-packages/torch/nn/modules/module.py", line 237, in __getattr__
    return object.__getattr__(self, name)
AttributeError: type object 'object' has no attribute '__getattr__'