Python download script (openai#89)

added python download script and modified requirements to add the modules needed. Tested in Windows Version 10.0.17134 Build 17134  and Ubuntu 18.04.1 LTS

download_model.py

@@ -0,0 +1,24 @@
+#!/usr/bin/env python
+import os
+import sys
+import requests
+from tqdm import tqdm
+
+if len(sys.argv)!=2:
+    print('You must enter the model name as a parameter, e.g.: download_model.py 117M')
+    sys.exit(1)
+model = sys.argv[1]
+#Create directory if it does not exist already, then do nothing
+if not os.path.exists('models/'+model):
+    os.makedirs('models/'+model)
+#download all the files
+for filename in ['checkpoint','encoder.json','hparams.json','model.ckpt.data-00000-of-00001', 'model.ckpt.index', 'model.ckpt.meta', 'vocab.bpe']:
+    r = requests.get("https://storage.googleapis.com/gpt-2/models/"+model+"/"+filename,stream=True)
+    #wb flag required for windows
+    with open('models/'+model+'/'+filename,'wb') as currentFile:
+        fileSize = int(r.headers["content-length"])
+        with tqdm(ncols=100,desc="Fetching "+filename,total=fileSize,unit_scale=True) as pbar:
+            #went for 1k for chunk_size. Motivation -> Ethernet packet size is around 1500 bytes.
+            for chunk in r.iter_content(chunk_size=1000):
+                currentFile.write(chunk)
+                pbar.update(1000)

requirements.txt

@@ -1,2 +1,4 @@
 fire>=0.1.3
 regex==2017.4.5
+requests==2.21.0
+tqdm==4.31.1