Lower search calls per second to 1

Fixes edgi-govdata-archiving#137

wayback/_client.py

@@ -347,7 +347,7 @@ class WaybackSession(_utils.DisableAfterCloseSession, requests.Session):
     user_agent : str, optional
         A custom user-agent string to use in all requests. Defaults to:
         `wayback/{version} (+https://github.com/edgi-govdata-archiving/wayback)`
-    search_calls_per_second : int or float, default: 1.5
+    search_calls_per_second : int or float, default: 1
         The maximum number of calls made to the search API per second.
         To disable the rate limit, set this to 0.
     memento_calls_per_second : int or float, default: 30
@@ -366,7 +366,7 @@ class WaybackSession(_utils.DisableAfterCloseSession, requests.Session):
     handleable_errors = (ConnectionError,) + retryable_errors
 
     def __init__(self, retries=6, backoff=2, timeout=60, user_agent=None,
-                 search_calls_per_second=1.5, memento_calls_per_second=30):
+                 search_calls_per_second=1, memento_calls_per_second=30):
         super().__init__()
         self.retries = retries
         self.backoff = backoff

wayback/_utils.py

@@ -204,7 +204,7 @@ def set_memento_url_mode(url, mode):
 
 
 @contextmanager
-def rate_limited(calls_per_second=2, group='default'):
+def rate_limited(calls_per_second=1, group='default'):
     """
     A context manager that restricts entries to its body to occur only N times
     per second (N can be a float). The current thread will be put to sleep in

wayback/tests/test_client.py

@@ -792,7 +792,7 @@ def test_search_rate_limits(self):
                 next(client.search('zew.de'))
         duration_with_limits_custom = time.time() - start_time
 
-        assert 1.3 <= duration_with_limits <= 1.4
+        assert 1.9 <= duration_with_limits <= 2.1
         assert 0.0 <= duration_without_limits <= 0.05
         assert 0.0 <= duration_with_limits_custom <= 1.05