Replaced the download_model method to the new one implemented in bob.extension

Closes #5 (closed)

@amohammadi I assigned this one to myself. If you feel reviewing this one, please go ahead

bob/ip/tensorflow_extractor/DrGanMSU.py

@@ -9,6 +9,7 @@ from bob.extension import rc
 from bob.extension.rc_config import _saverc
 from . import download_file
 import logging
+import bob.extension
 logger = logging.getLogger(__name__)
 
 
@@ -352,8 +353,16 @@ class DrGanMSUExtractor(object):
 
         # If does not exist, download
         if not os.path.exists(model_path):
-            self.download_model()
-                
+            zip_file = os.path.join(DrGanMSUExtractor.get_modelpath(),
+                                    "DR_GAN_model.zip")
+            urls = [
+                # This is a private link at Idiap to save bandwidth.
+                "http://www.idiap.ch/private/wheels/gitlab/"
+                "DR_GAN_model.zip",
+            ]
+
+            bob.extension.download.download_and_unzip(urls, zip_file)
+
         self.saver = tf.train.Saver()
         # Reestore either from the last checkpoint or from a particular checkpoint
         if os.path.isdir(model_path):
@@ -381,46 +390,6 @@ class DrGanMSUExtractor(object):
         return "bob.ip.tensorflow_extractor.drgan_modelpath"
 
 
-    @staticmethod
-    def download_model():
-        """
-        Download and extract the DrGanMSU files in bob/ip/tensorflow_extractor
-        """
-        import zipfile
-        zip_file = os.path.join(DrGanMSUExtractor.get_modelpath(),
-                                "DR_GAN_model.zip")
-        urls = [
-            # This is a private link at Idiap to save bandwidth.
-            "http://beatubulatest.lab.idiap.ch/private/wheels/gitlab/"
-            "DR_GAN_model.zip",
-        ]
-
-        for url in urls:
-            try:
-                logger.info(
-                    "Downloading the DrGanMSU model from "
-                    "{} ...".format(url))
-                download_file(url, zip_file)
-                break
-            except Exception:
-                logger.warning(
-                    "Could not download from the %s url", url, exc_info=True)
-        else:  # else is for the for loop
-            if not os.path.isfile(zip_file):
-                raise RuntimeError("Could not download the zip file.")
-
-        # Unzip
-        logger.info("Unziping in {0}".format(DrGanMSUExtractor.get_modelpath()))
-        with zipfile.ZipFile(zip_file) as myzip:
-            myzip.extractall(os.path.dirname(DrGanMSUExtractor.get_modelpath()))
-
-        logger.info("Saving the path `{0}` in the ~.bobrc file".format(DrGanMSUExtractor.get_modelpath()))
-        rc[DrGanMSUExtractor.get_rcvariable()] = DrGanMSUExtractor.get_modelpath()
-        _saverc(rc)
-
-        # delete extra files
-        os.unlink(zip_file)
-
     def __call__(self, image):
         """__call__(image) -> feature