Issue #4486: When an exception has an explicit cause, do not print its implicit context too.
diff --git a/Lib/traceback.py b/Lib/traceback.py
index c0d8061..8d4e96e 100644
--- a/Lib/traceback.py
+++ b/Lib/traceback.py
@@ -120,13 +120,14 @@
seen.add(exc)
its = []
cause = exc.__cause__
- context = exc.__context__
if cause is not None and cause not in seen:
its.append(_iter_chain(cause, None, seen))
its.append([(_cause_message, None)])
- if context is not None and context is not cause and context not in seen:
- its.append(_iter_chain(context, None, seen))
- its.append([(_context_message, None)])
+ else:
+ context = exc.__context__
+ if context is not None and context not in seen:
+ its.append(_iter_chain(context, None, seen))
+ its.append([(_context_message, None)])
its.append([(exc, custom_tb or exc.__traceback__)])
# itertools.chain is in an extension module and may be unavailable
for it in its: