routing: stop printing warning if the user passes a wrong URL

When a _lookup method accepts N + *remainder arguments but the number of
path components (separated by /) is < N, a TypeError is raised when calling the
object and Pecan prints a RuntimeWarning that is log. Unfortunately this just
fills up the log with no interesting information for the developer as this is
just a standard 404 error.

pecan/routing.py

@@ -1,3 +1,4 @@
+import logging
 import re
 import warnings
 from inspect import getmembers, ismethod
@@ -12,6 +13,8 @@ __all__ = ['lookup_controller', 'find_object', 'route']
 __observed_controllers__ = set()
 __custom_routes__ = {}
 
+logger = logging.getLogger(__name__)
+
 
 def route(*args):
     """
@@ -177,11 +180,8 @@ def handle_lookup_traversal(obj, args):
             cross_boundary(prev_obj, obj)
             return result
     except TypeError as te:
-        msg = 'Got exception calling lookup(): %s (%s)'
-        warnings.warn(
-            msg % (te, te.args),
-            RuntimeWarning
-        )
+        logger.debug('Got exception calling lookup(): %s (%s)',
+                     te, te.args)
 
 
 def find_object(obj, remainder, notfound_handlers, request):

pecan/tests/test_base.py

@@ -339,11 +339,9 @@ class TestLookups(PecanTestCase):
             def _lookup(self, someID):
                 return 'Bad arg spec'  # pragma: nocover
 
-        with warnings.catch_warnings():
-            warnings.simplefilter("ignore")
-            app = TestApp(Pecan(RootController()))
-            r = app.get('/foo/bar', expect_errors=True)
-            assert r.status_int == 404
+        app = TestApp(Pecan(RootController()))
+        r = app.get('/foo/bar', expect_errors=True)
+        assert r.status_int == 404
 
 
 class TestCanonicalLookups(PecanTestCase):