Use new syntax instead of py::arg
Use new syntax instead of py::arg

pfnet/chainer,wkentaro/chainer,wkentaro/chainer,niboshi/chainer,chainer/chainer,niboshi/chainer,wkentaro/chainer,chainer/chainer,wkentaro/chainer,hvy/chainer,hvy/chainer,hvy/chainer,hvy/chainer,chainer/chainer,chainer/chainer,niboshi/chainer,niboshi/chainer