Clearer exception messages when _BaseCell.get_child or Node.lookup_st…

…r are passed bad parameters

spinoff/actor/cell.py

@@ -88,7 +88,7 @@ def _child_gone(self, child):
 
     def get_child(self, name):
         if not (name and isinstance(name, str)):
-            raise TypeError("get_child takes a non-emtpy string")  # pragma: no cover
+            raise TypeError("get_child takes a non-emtpy string not %r" % (name,))  # pragma: no cover
         return self._children.get(name, None)
 
     def lookup_cell(self, uri):

spinoff/actor/node.py

@@ -34,6 +34,8 @@ def __init__(self, nid=None, enable_remoting=False, enable_relay=False, hub_kwar
         )
 
     def lookup_str(self, addr):
+        if not isinstance(addr, str):
+            raise TypeError("%s.lookup_str expects a str" % type(self).__name__)  # pragma: no cover
         return self.lookup(Uri.parse(addr))
 
     def lookup(self, uri):