Add compat helpers for urllib

spacy/compat.py

@@ -33,11 +33,23 @@ try:
 except ImportError:
     from thinc.neural.optimizers import Adam as Optimizer
 
+try:
+    import urllib
+except ImportError:
+    import urllib2 as urllib
+
+try:
+    from urllib.error import HTTPError as url_error
+except ImportError:
+    from urllib2 import HTTPError as url_error
+
 pickle = pickle
 copy_reg = copy_reg
 CudaStream = CudaStream
 cupy = cupy
 copy_array = copy_array
+urllib = urllib
+url_error = url_error
 izip = getattr(itertools, 'izip', zip)
 
 is_windows = sys.platform.startswith('win')
@@ -56,6 +68,7 @@ if is_python2:
     input_ = raw_input  # noqa: F821
     json_dumps = lambda data: ujson.dumps(data, indent=2, escape_forward_slashes=False).decode('utf8')
     path2str = lambda path: str(path).decode('utf8')
+    url_open = lambda url: urllib.urlopen(url)
 
 elif is_python3:
     bytes_ = bytes
@@ -64,6 +77,7 @@ elif is_python3:
     input_ = input
     json_dumps = lambda data: ujson.dumps(data, indent=2, escape_forward_slashes=False)
     path2str = lambda path: str(path)
+    url_open = lambda url: urllib.request.urlopen(url)
 
 
 def b_to_str(b_str):