contextlib: modify ExitStack to work in uPy

contextlib/contextlib.py

@@ -165,15 +165,12 @@ def __exit__(self, exctype, excinst, exctb):
 # Inspired by discussions on http://bugs.python.org/issue13585
 class ExitStack(object):
     """Context manager for dynamic management of a stack of exit callbacks
-
     For example:
-
         with ExitStack() as stack:
             files = [stack.enter_context(open(fname)) for fname in filenames]
             # All opened files will automatically be closed at the end of
             # the with statement, even if attempts to open files later
             # in the list raise an exception
-
     """
     def __init__(self):
         self._exit_callbacks = deque()
@@ -189,14 +186,11 @@ def _push_cm_exit(self, cm, cm_exit):
         """Helper to correctly register callbacks to __exit__ methods"""
         def _exit_wrapper(*exc_details):
             return cm_exit(cm, *exc_details)
-        _exit_wrapper.__self__ = cm
         self.push(_exit_wrapper)
 
     def push(self, exit):
         """Registers a callback with the standard __exit__ method signature
-
         Can suppress exceptions the same way __exit__ methods can.
-
         Also accepts any object with an __exit__ method (registering a call
         to the method instead of the object itself)
         """
@@ -214,20 +208,15 @@ def push(self, exit):
 
     def callback(self, callback, *args, **kwds):
         """Registers an arbitrary callback and arguments.
-
         Cannot suppress exceptions.
         """
         def _exit_wrapper(exc_type, exc, tb):
             callback(*args, **kwds)
-        # We changed the signature, so using @wraps is not appropriate, but
-        # setting __wrapped__ may still help with introspection
-        _exit_wrapper.__wrapped__ = callback
         self.push(_exit_wrapper)
         return callback # Allow use as a decorator
 
     def enter_context(self, cm):
         """Enters the supplied context manager
-
         If successful, also pushes its __exit__ method as a callback and
         returns the result of the __enter__ method.
         """