better exception handling in matcher

Signed-off-by: Yoch Melka <yoch.melka@gmail.com>

Author: yoch

src/paho/mqtt/matcher.py

@@ -30,11 +30,12 @@ def __getitem__(self, key):
             node = self._root
             for sym in key.split('/'):
                 node = node._children[sym]
+        except KeyError as err:
+            raise KeyError(key) from err
+        else:
             if node._content is None:
                 raise KeyError(key)
             return node._content
-        except KeyError as ke:
-            raise KeyError(key) from ke
 
     def __delitem__(self, key):
         """Delete the value associated with some topic filter :key"""
@@ -44,11 +45,13 @@ def __delitem__(self, key):
             for k in key.split('/'):
                  parent, node = node, node._children[k]
                  lst.append((parent, k, node))
-            # TODO
+        except KeyError as err:
+            raise KeyError(key) from err
+        else:
+            if node._content is None:
+                raise KeyError(key)
             node._content = None
-        except KeyError as ke:
-            raise KeyError(key) from ke
-        else:  # cleanup
+            # cleanup
             for parent, k, node in reversed(lst):
                 if node._children or node._content is not None:
                      break
@@ -66,11 +69,9 @@ def rec(node, i=0):
             else:
                 part = lst[i]
                 if part in node._children:
-                    for content in rec(node._children[part], i + 1):
-                        yield content
+                    yield from rec(node._children[part], i + 1)
                 if '+' in node._children and (normal or i > 0):
-                    for content in rec(node._children['+'], i + 1):
-                        yield content
+                    yield from rec(node._children['+'], i + 1)
             if '#' in node._children and (normal or i > 0):
                 content = node._children['#']._content
                 if content is not None:

tests/test_matcher.py

@@ -17,6 +17,7 @@ class Test_client_function:
         ("#", "/foo/bar"),
         ("/#", "/foo/bar"),
         ("$SYS/bar", "$SYS/bar"),
+        ("$SYS/#", "$SYS/foo/bar"),
     ])
     def test_matching(self, sub, topic):
         assert client.topic_matches_sub(sub, topic)