diff --git a/GPy/util/datasets.py b/GPy/util/datasets.py
index 0e36616f..2d1d3244 100644
--- a/GPy/util/datasets.py
+++ b/GPy/util/datasets.py
@@ -73,7 +73,7 @@ def prompt_user(prompt):
 
     try:
         print(prompt)
-        choice = raw_input().lower()
+        choice = input().lower()
         # would like to test for exception here, but not sure if we can do that without importing IPython
     except:
         print('Stdin is not implemented.')
@@ -96,16 +96,16 @@ def prompt_user(prompt):
 def data_available(dataset_name=None):
     """Check if the data set is available on the local machine already."""
     try:
-        from itertools import izip_longest
+        from itertools import zip_longest
     except ImportError:
-        from itertools import zip_longest as izip_longest
+        from itertools import zip_longest as zip_longest
     dr = data_resources[dataset_name]
     zip_urls = (dr['files'], )
     if 'save_names' in dr: zip_urls += (dr['save_names'], )
     else: zip_urls += ([],)
 
-    for file_list, save_list in izip_longest(*zip_urls, fillvalue=[]):
-        for f, s in izip_longest(file_list, save_list, fillvalue=None):
+    for file_list, save_list in zip_longest(*zip_urls, fillvalue=[]):
+        for f, s in zip_longest(file_list, save_list, fillvalue=None):
             if s is not None: f=s # If there is a save_name given, use that one
             if not os.path.exists(os.path.join(data_path, dataset_name, f)):
                 return False
@@ -138,7 +138,7 @@ def download_url(url, store_directory, save_name=None, messages=True, suffix='')
             raise ValueError('Tried url ' + url + suffix + ' and received server error ' + str(response.code))
     with open(save_name, 'wb') as f:
         meta = response.info()
-        content_length_str = meta.getheaders("Content-Length")
+        content_length_str = meta.get("Content-Length")
         if content_length_str:
             file_size = int(content_length_str[0])
         else:
@@ -220,8 +220,8 @@ def download_data(dataset_name=None):
     if 'suffices' in dr: zip_urls += (dr['suffices'], )
     else: zip_urls += ([],)
 
-    for url, files, save_names, suffices in itertools.izip_longest(*zip_urls, fillvalue=[]):
-        for f, save_name, suffix in itertools.izip_longest(files, save_names, suffices, fillvalue=None):
+    for url, files, save_names, suffices in itertools.zip_longest(*zip_urls, fillvalue=[]):
+        for f, save_name, suffix in itertools.zip_longest(files, save_names, suffices, fillvalue=None):
             download_url(os.path.join(url,f), dataset_name, save_name, suffix=suffix)
 
     return True