[Model Zoo] Fix JTNN (#843)

* Update

* Update

* Update

* Update

* Update

python/dgl/model_zoo/chem/jtnn/jtnn_vae.py

 # pylint: disable=C0111, C0103, E1101, W0611, W0612, C0200
 import copy
-import math
 
 import torch
 import torch.nn as nn
 import torch.nn.functional as F
 
-import rdkit
 import rdkit.Chem as Chem
-from rdkit import DataStructs
-from rdkit.Chem import AllChem
 
 from dgl import batch, unbatch
 from dgl.data.utils import get_download_dir
@@ -23,7 +19,7 @@ from .jtnn_enc import DGLJTNNEncoder
 from .mol_tree import Vocab
 from .mpn import DGLMPN
 from .mpn import mol2dgl_single as mol2dgl_enc
-from .nnutils import create_var, cuda, move_dgl_to_cuda
+from .nnutils import cuda, move_dgl_to_cuda
 
 
 class DGLJTNNVAE(nn.Module):
@@ -37,9 +33,7 @@ class DGLJTNNVAE(nn.Module):
             if vocab_file is None:
                 vocab_file = '{}/jtnn/{}.txt'.format(
                     get_download_dir(), 'vocab')
-                self.vocab = Vocab([x.strip("\r\n ")
-                                    for x in open(vocab_file)])
-            else:
+
             self.vocab = Vocab([x.strip("\r\n ")
                                 for x in open(vocab_file)])
         else:
@@ -125,7 +119,6 @@ class DGLJTNNVAE(nn.Module):
         assm_loss, assm_acc = self.assm(mol_batch, mol_tree_batch, mol_vec)
         stereo_loss, stereo_acc = self.stereo(mol_batch, mol_vec)
 
-        all_vec = torch.cat([tree_vec, mol_vec], dim=1)
         loss = word_loss + topo_loss + assm_loss + 2 * stereo_loss + beta * kl_loss
 
         return loss, kl_loss, word_acc, topo_acc, assm_acc, stereo_acc

python/dgl/model_zoo/chem/jtnn/mol_tree.py

 # pylint: disable=C0111, C0103, E1101, W0611, W0612
 import copy
 
-import rdkit
 import rdkit.Chem as Chem
 
 

python/dgl/model_zoo/chem/jtnn/mpn.py

 # pylint: disable=C0111, C0103, E1101, W0611, W0612
 # pylint: disable=redefined-outer-name
-from functools import partial
-
-import numpy as np
 import rdkit.Chem as Chem
 import torch
 import torch.nn as nn
 import torch.nn.functional as F
 import dgl.function as DGLF
-from dgl import DGLGraph, batch, mean_nodes, unbatch
-from networkx import DiGraph, Graph, convert_node_labels_to_integers
+from dgl import DGLGraph, mean_nodes
 
 from .chemutils import get_mol
-# from .nnutils import *
 
 ELEM_LIST = ['C', 'N', 'O', 'S', 'F', 'Si', 'P', 'Cl', 'Br', 'Mg', 'Na',
              'Ca', 'Fe', 'Al', 'I', 'B', 'K', 'Se', 'Zn', 'H', 'Cu', 'Mn', 'unknown']

python/dgl/model_zoo/chem/pretrain.py

 """Utilities for using pretrained models."""
+import os
 import torch
 from rdkit import Chem
 
@@ -8,7 +9,7 @@ from .dgmg import DGMG
 from .mgcn import MGCNModel
 from .mpnn import MPNNModel
 from .schnet import SchNet
-from ...data.utils import _get_dgl_url, download, get_download_dir
+from ...data.utils import _get_dgl_url, download, get_download_dir, extract_archive
 
 URL = {
     'GCN_Tox21' : 'pre_trained/gcn_tox21.pth',
@@ -122,7 +123,13 @@ def load_pretrained(model_name, log=True):
         model = MPNNModel(output_dim=12)
 
     elif model_name == "JTNN_ZINC":
-        vocab_file = '{}/jtnn/{}.txt'.format(get_download_dir(), 'vocab')
+        default_dir = get_download_dir()
+        vocab_file = '{}/jtnn/{}.txt'.format(default_dir, 'vocab')
+        if not os.path.exists(vocab_file):
+            zip_file_path = '{}/jtnn.zip'.format(default_dir)
+            download('https://s3-ap-southeast-1.amazonaws.com/dgl-data-cn/dataset/jtnn.zip',
+                     path=zip_file_path)
+            extract_archive(zip_file_path, '{}/jtnn'.format(default_dir))
         model = DGLJTNNVAE(vocab_file=vocab_file,
                            depth=3,
                            hidden_size=450,