--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/symbian-qemu-0.9.1-12/python-win32-2.6.1/lib/contextlib.py Fri Jul 31 15:01:17 2009 +0100
@@ -0,0 +1,153 @@
+"""Utilities for with-statement contexts. See PEP 343."""
+
+import sys
+from functools import wraps
+
+__all__ = ["contextmanager", "nested", "closing"]
+
+class GeneratorContextManager(object):
+ """Helper for @contextmanager decorator."""
+
+ def __init__(self, gen):
+ self.gen = gen
+
+ def __enter__(self):
+ try:
+ return self.gen.next()
+ except StopIteration:
+ raise RuntimeError("generator didn't yield")
+
+ def __exit__(self, type, value, traceback):
+ if type is None:
+ try:
+ self.gen.next()
+ except StopIteration:
+ return
+ else:
+ raise RuntimeError("generator didn't stop")
+ else:
+ if value is None:
+ # Need to force instantiation so we can reliably
+ # tell if we get the same exception back
+ value = type()
+ try:
+ self.gen.throw(type, value, traceback)
+ raise RuntimeError("generator didn't stop after throw()")
+ except StopIteration, exc:
+ # Suppress the exception *unless* it's the same exception that
+ # was passed to throw(). This prevents a StopIteration
+ # raised inside the "with" statement from being suppressed
+ return exc is not value
+ except:
+ # only re-raise if it's *not* the exception that was
+ # passed to throw(), because __exit__() must not raise
+ # an exception unless __exit__() itself failed. But throw()
+ # has to raise the exception to signal propagation, so this
+ # fixes the impedance mismatch between the throw() protocol
+ # and the __exit__() protocol.
+ #
+ if sys.exc_info()[1] is not value:
+ raise
+
+
+def contextmanager(func):
+ """@contextmanager decorator.
+
+ Typical usage:
+
+ @contextmanager
+ def some_generator(<arguments>):
+ <setup>
+ try:
+ yield <value>
+ finally:
+ <cleanup>
+
+ This makes this:
+
+ with some_generator(<arguments>) as <variable>:
+ <body>
+
+ equivalent to this:
+
+ <setup>
+ try:
+ <variable> = <value>
+ <body>
+ finally:
+ <cleanup>
+
+ """
+ @wraps(func)
+ def helper(*args, **kwds):
+ return GeneratorContextManager(func(*args, **kwds))
+ return helper
+
+
+@contextmanager
+def nested(*managers):
+ """Support multiple context managers in a single with-statement.
+
+ Code like this:
+
+ with nested(A, B, C) as (X, Y, Z):
+ <body>
+
+ is equivalent to this:
+
+ with A as X:
+ with B as Y:
+ with C as Z:
+ <body>
+
+ """
+ exits = []
+ vars = []
+ exc = (None, None, None)
+ try:
+ for mgr in managers:
+ exit = mgr.__exit__
+ enter = mgr.__enter__
+ vars.append(enter())
+ exits.append(exit)
+ yield vars
+ except:
+ exc = sys.exc_info()
+ finally:
+ while exits:
+ exit = exits.pop()
+ try:
+ if exit(*exc):
+ exc = (None, None, None)
+ except:
+ exc = sys.exc_info()
+ if exc != (None, None, None):
+ # Don't rely on sys.exc_info() still containing
+ # the right information. Another exception may
+ # have been raised and caught by an exit method
+ raise exc[0], exc[1], exc[2]
+
+
+class closing(object):
+ """Context to automatically close something at the end of a block.
+
+ Code like this:
+
+ with closing(<module>.open(<arguments>)) as f:
+ <block>
+
+ is equivalent to this:
+
+ f = <module>.open(<arguments>)
+ try:
+ <block>
+ finally:
+ f.close()
+
+ """
+ def __init__(self, thing):
+ self.thing = thing
+ def __enter__(self):
+ return self.thing
+ def __exit__(self, *exc_info):
+ self.thing.close()