Implement panic() with magic methods rather than @contextmanager

Author: hannes-ucsc

src/bd2k/util/exceptions.py

@@ -2,8 +2,7 @@
 import sys
 
 
-@contextmanager
-def panic( log=None ):
+class panic( object ):
     """
     The Python idiom for reraising a primary exception fails when the except block raises a
     secondary exception, e.g. while trying to cleanup. In that case the original exception is
@@ -21,13 +20,18 @@ def panic( log=None ):
     If a logging logger is passed to panic(), any secondary Exception raised within the with
     block will be logged. Otherwise those exceptions are swallowed. At the end of the with block
     the primary exception will be reraised.
-
     """
-    exc_type, exc_value, traceback = sys.exc_info( )
-    try:
-        yield
-    except Exception as e:
-        if log is not None:
-            log.warn( "Exception during panic", exc_info=True )
-    finally:
+
+    def __init__( self, log=None ):
+        super( panic, self ).__init__( )
+        self.log = log
+        self.exc_info = None
+
+    def __enter__( self ):
+        self.exc_info = sys.exc_info( )
+
+    def __exit__( self, *exc_info ):
+        if self.log is not None:
+            self.log.warn( "Exception during panic", exc_info=exc_info )
+        exc_type, exc_value, traceback = self.exc_info
         raise exc_type, exc_value, traceback