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Editing: contextlib.cpython-34.pyc
� e fw- � @ s� d Z d d l Z d d l m Z d d l m Z d d d d d d g Z Gd d � d e � Z Gd d � d e � Z d d � Z Gd d � d e � Z Gd d � d � Z Gd d � d � Z Gd d � d e � Z d S)z4Utilities for with-statement contexts. See PEP 343.� N)�deque)�wraps�contextmanager�closing�ContextDecorator� ExitStack�redirect_stdout�suppressc @ s. e Z d Z d Z d d � Z d d � Z d S)r zJA base class or mixin that enables context managers to work as decorators.c C s | S)a6 Return a recreated instance of self. Allows an otherwise one-shot context manager like _GeneratorContextManager to support use as a decorator via implicit recreation. This is a private interface just for _GeneratorContextManager. See issue #11647 for details. � )�selfr r �//opt/alt/python34/lib64/python3.4/contextlib.py� _recreate_cm s z ContextDecorator._recreate_cmc s% t � � � � f d d � � } | S)Nc s$ � j � � � | | � SWd QXd S)N)r )�args�kwds)�funcr r r �inner s z(ContextDecorator.__call__.<locals>.inner)r )r r r r )r r r �__call__ s !zContextDecorator.__call__N)�__name__� __module__� __qualname__�__doc__r r r r r r r s c @ sF e Z d Z d Z d d � Z d d � Z d d � Z d d � Z d S) �_GeneratorContextManagerz%Helper for @contextmanager decorator.c C sl | | | � | _ | | | | _ | _ | _ t | d d � } | d k r_ t | � j } n | | _ d S)Nr )�genr r r �getattr�typer )r r r r �docr r r �__init__% s z!_GeneratorContextManager.__init__c C s | j | j | j | j � S)N)� __class__r r r )r r r r r 3 s z%_GeneratorContextManager._recreate_cmc C s9 y t | j � SWn! t k r4 t d � d � Yn Xd S)Nzgenerator didn't yield)�nextr � StopIteration� RuntimeError)r r r r � __enter__9 s z"_GeneratorContextManager.__enter__c C s� | d k rE y t | j � Wn t k r5 d SYq� Xt d � � n� | d k r] | � } n y& | j j | | | � t d � � WnR t k r� } z | | k SWYd d } ~ Xn$ t j � d | k r� � n Yn Xd S)Nzgenerator didn't stopz#generator didn't stop after throw()� )r r r r �throw�sys�exc_info)r r �value� traceback�excr r r �__exit__? s z!_GeneratorContextManager.__exit__N)r r r r r r r! r) r r r r r " s r c s" t � � � f d d � � } | S)a� @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> c s t � | | � S)N)r )r r )r r r �helper| s z contextmanager.<locals>.helper)r )r r* r )r r r ` s c @ s: e Z d Z d Z d d � Z d d � Z d d � Z d S) r a2 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() c C s | | _ d S)N)�thing)r r+ r r r r � s zclosing.__init__c C s | j S)N)r+ )r r r r r! � s zclosing.__enter__c G s | j j � d S)N)r+ �close)r r% r r r r) � s zclosing.__exit__N)r r r r r r! r) r r r r r � s c @ s: e Z d Z d Z d d � Z d d � Z d d � Z d S) r a@ Context manager for temporarily redirecting stdout to another file # How to send help() to stderr with redirect_stdout(sys.stderr): help(dir) # How to write help() to a file with open('help.txt', 'w') as f: with redirect_stdout(f): help(pow) c C s | | _ g | _ d S)N)� _new_target� _old_targets)r � new_targetr r r r � s zredirect_stdout.__init__c C s& | j j t j � | j t _ | j S)N)r. �appendr$ �stdoutr- )r r r r r! � s zredirect_stdout.__enter__c C s | j j � t _ d S)N)r. �popr$ r1 )r �exctype�excinst�exctbr r r r) � s zredirect_stdout.__exit__N)r r r r r r! r) r r r r r � s c @ s: e Z d Z d Z d d � Z d d � Z d d � Z d S) r a? Context manager to suppress specified exceptions After the exception is suppressed, execution proceeds with the next statement following the with statement. with suppress(FileNotFoundError): os.remove(somefile) # Execution still resumes here if the file was already removed c G s | | _ d S)N)� _exceptions)r � exceptionsr r r r � s zsuppress.__init__c C s d S)Nr )r r r r r! � s zsuppress.__enter__c C s | d k o t | | j � S)N)� issubclassr6 )r r3 r4 r5 r r r r) � s zsuppress.__exit__N)r r r r r r! r) r r r r r � s c @ s� e Z d Z d Z d d � Z d d � Z d d � Z d d � Z d d � Z d d � Z d d � Z d d � Z d d � Z d S)r a� 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 c C s t � | _ d S)N)r �_exit_callbacks)r r r r r � s zExitStack.__init__c C s+ t | � � } | j | _ t � | _ | S)z?Preserve the context stack by transferring it to a new instance)r r9 r )r � new_stackr r r �pop_all� s zExitStack.pop_allc s/ � � f d d � } � | _ | j | � d S)z:Helper to correctly register callbacks to __exit__ methodsc s � � | � S)Nr )� exc_details)�cm�cm_exitr r � _exit_wrapper� s z.ExitStack._push_cm_exit.<locals>._exit_wrapperN)�__self__�push)r r= r> r? r )r= r> r � _push_cm_exit� s zExitStack._push_cm_exitc C sR t | � } y | j } Wn" t k r= | j j | � Yn X| j | | � | S)a 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) )r r) �AttributeErrorr9 r0 rB )r �exit�_cb_type� exit_methodr r r rA � s zExitStack.pushc s2 � � � f d d � } � | _ | j | � � S)z\Registers an arbitrary callback and arguments. Cannot suppress exceptions. c s � � � � d S)Nr )�exc_typer( �tb)r �callbackr r r r? s z)ExitStack.callback.<locals>._exit_wrapper)� __wrapped__rA )r rI r r r? r )r rI r r rI s zExitStack.callbackc C s8 t | � } | j } | j | � } | j | | � | S)z�Enters the supplied context manager If successful, also pushes its __exit__ method as a callback and returns the result of the __enter__ method. )r r) r! rB )r r= �_cm_type�_exit�resultr r r � enter_context s zExitStack.enter_contextc C s | j d d d � d S)z$Immediately unwind the context stackN)r) )r r r r r, s zExitStack.closec C s | S)Nr )r r r r r! # s zExitStack.__enter__c s | d d k } t j � d � � f d d � } d } d } xy | j r� | j j � } y% | | � r} d } d } d } n WqA t j � } | | d | d � d } | } YqA XqA W| ry | d j } | d � Wqt k r� | | d _ � YqXn | o | S)Nr r" c sO x? | j } | | k r d S| d k s4 | � k r8 Pn | } q W| | _ d S)N)� __context__)�new_exc�old_exc� exc_context)� frame_excr r �_fix_exception_context, s z2ExitStack.__exit__.<locals>._fix_exception_contextFT)NNN)r$ r% r9 r2 rO � BaseException) r r< � received_excrT �suppressed_exc� pending_raise�cb�new_exc_details� fixed_ctxr )rS r r) & s2 zExitStack.__exit__N) r r r r r r; rB rA rI rN r, r! r) r r r r r � s )r r$ � collectionsr � functoolsr �__all__�objectr r r r r r r r r r r �<module> s > "
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