add wmt14 pretrained model

Author: luotao1

python/paddle/v2/dataset/wmt14.py

@@ -15,8 +15,10 @@
 wmt14 dataset
 """
 import tarfile
+import gzip
 
 from paddle.v2.dataset.common import download
+from paddle.v2.parameters import Parameters
 
 __all__ = ['train', 'test', 'build_dict']
 
@@ -25,6 +27,9 @@
 # this is a small set of data for test. The original data is too large and will be add later.
 URL_TRAIN = 'http://paddlepaddle.cdn.bcebos.com/demo/wmt_shrinked_data/wmt14.tgz'
 MD5_TRAIN = 'a755315dd01c2c35bde29a744ede23a6'
+# this is the pretrained model, whose bleu = 26.92
+URL_MODEL = 'http://paddlepaddle.bj.bcebos.com/demo/wmt_14/wmt14_model.tar.gz'
+MD5_MODEL = '6b097d23e15654608c6f74923e975535'
 
 START = "<s>"
 END = "<e>"
@@ -103,5 +108,13 @@ def test(dict_size):
         download(URL_TRAIN, 'wmt14', MD5_TRAIN), 'test/test', dict_size)
 
 
+def model():
+    tar_file = download(URL_MODEL, 'wmt14', MD5_MODEL)
+    with gzip.open(tar_file, 'r') as f:
+        parameters = Parameters.from_tar(f)
+    return parameters
+
+
 def fetch():
     download(URL_TRAIN, 'wmt14', MD5_TRAIN)
+    download(URL_MODEL, 'wmt14', MD5_MODEL)