1 files changed, 16 insertions, 1 deletions
diff --git a/Lib/bdb.py b/Lib/bdb.py
index ec0f92c06a7..54aa9843745 100644
--- a/Lib/bdb.py
+++ b/Lib/bdb.py
@@ -618,11 +618,26 @@ class Bdb:
 
     # This method is more useful to debug a single function call.
 
-    def runcall(self, func, *args, **kwds):
+    def runcall(*args, **kwds):
         """Debug a single function call.
 
         Return the result of the function call.
         """
+        if len(args) >= 2:
+            self, func, *args = args
+        elif not args:
+            raise TypeError("descriptor 'runcall' of 'Bdb' object "
+                            "needs an argument")
+        elif 'func' in kwds:
+            func = kwds.pop('func')
+            self, *args = args
+            import warnings
+            warnings.warn("Passing 'func' as keyword argument is deprecated",
+                          DeprecationWarning, stacklevel=2)
+        else:
+            raise TypeError('runcall expected at least 1 positional argument, '
+                            'got %d' % (len(args)-1))
+
         self.reset()
         sys.settrace(self.trace_dispatch)
         res = None