updates due to feedback

Author: ceb8

astroquery/__init__.py

@@ -46,7 +46,8 @@ class Cache_Conf(_config.ConfigNamespace):
 
     cache_timeout = _config.ConfigItem(
         604800,
-        'Astroquery-wide cache timeout (seconds). Default is 1 week (604800).',
+        ('Astroquery-wide cache timeout (seconds). Default is 1 week (604800). '
+         'Setting to None prevents the cache from expiring (not recommended).'),
         cfgtype='integer'
     )
 

astroquery/query.py

@@ -35,7 +35,7 @@ def to_cache(response, cache_file):
         for key in tuple(response.request.hooks.keys()):
             del response.request.hooks[key]
     with open(cache_file, "wb") as f:
-        pickle.dump(response, f)
+        pickle.dump(response, f, protocol=4)
 
 
 def _replace_none_iterable(iterable):
@@ -284,7 +284,7 @@ def _request(self, method, url,
             somewhere other than `BaseQuery.cache_location`
         timeout : int
         cache : bool
-            Override global cache settings.
+            Optional, if specified, overrides global cache settings.
         verify : bool
             Verify the server's TLS certificate?
             (see http://docs.python-requests.org/en/master/_modules/requests/sessions/?highlight=verify)

astroquery/tests/test_cache.py

@@ -167,13 +167,20 @@ def test_timeout(monkeypatch):
     assert resp.content == TEXT1
 
     # Changing the file date so the cache will consider it expired
-    cache_file = list(mytest.cache_location.iterdir())[0]
+    cache_file = next(mytest.cache_location.iterdir())
     modTime = mktime(datetime(1970, 1, 1).timetuple())
     os.utime(cache_file, (modTime, modTime))
-    
+
     resp = mytest.test_func(URL1)
     assert resp.content == TEXT2  # now see the new response
 
+    # Testing a cache timeout of "none"
+    cache_conf.cache_timeout = None
+    set_response(TEXT1)
+
+    resp = mytest.test_func(URL1)
+    assert resp.content == TEXT2 # cache is accessed
+
 
 def test_deactivate():
     cache_conf.reset()

docs/index.rst

@@ -195,17 +195,15 @@ Shown here are the cache properties, using Simbad as an example:
 
   >>> from astroquery import cache_conf
   >>> from astroquery.simbad import Simbad
-
+  ...
   >>> # Is the cache active?
   >>> print(cache_conf.cache_active)
   True
-
   >>> # Cache timout in seconds
   >>> print(cache_conf.cache_timeout)
   604800
-  
   >>> # Cache location
-  >>> print(Simbad.cache_location)
+  >>> print(Simbad.cache_location)   # doctest: +IGNORE_OUTPUT
   /Users/username/.astropy/cache/astroquery/Simbad