Edit File: contextlib.cpython-37.pyc
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See PEP 343.� N)�deque)�wraps�asynccontextmanager�contextmanager�closing� nullcontext�AbstractContextManager�AbstractAsyncContextManager�AsyncExitStack�ContextDecorator� ExitStack�redirect_stdout�redirect_stderr�suppressc @ s2 e Zd ZdZdd� Zejdd� �Zedd� �Z dS ) r z,An abstract base class for context managers.c C s | S )z0Return `self` upon entering the runtime context.� )�selfr r �//opt/alt/python37/lib64/python3.7/contextlib.py� __enter__ s z AbstractContextManager.__enter__c C s dS )z9Raise any exception triggered within the runtime context.Nr )r �exc_type� exc_value� tracebackr r r �__exit__ s z AbstractContextManager.__exit__c C s | t krt�|dd�S tS )Nr r )r �_collections_abc�_check_methods�NotImplemented)�cls�Cr r r �__subclasshook__ s z'AbstractContextManager.__subclasshook__N) �__name__� __module__� __qualname__�__doc__r �abc�abstractmethodr � classmethodr r r r r r s c @ s2 e Zd ZdZdd� Zejdd� �Zedd� �Z dS ) r z9An abstract base class for asynchronous context managers.c � s | S )z0Return `self` upon entering the runtime context.r )r r r r � __aenter__& s z&AbstractAsyncContextManager.__aenter__c � s dS )z9Raise any exception triggered within the runtime context.Nr )r r r r r r r � __aexit__* s z%AbstractAsyncContextManager.__aexit__c C s | t krt�|dd�S tS )Nr% r& )r r r r )r r r r r r / s z,AbstractAsyncContextManager.__subclasshook__N) r r r r! r% r" r# r& r$ r r r r r r " s c @ s e Zd ZdZdd� Zdd� ZdS )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. r )r r r r � _recreate_cm: s z ContextDecorator._recreate_cmc s t � �� �fdd��}|S )Nc s �� � � � | |�S Q R X d S )N)r' )�args�kwds)�funcr r r �innerG s z(ContextDecorator.__call__.<locals>.inner)r )r r* r+ r )r* r r �__call__F s zContextDecorator.__call__N)r r r r! r' r, r r r r r 7 s c @ s e Zd ZdZdd� ZdS )� _GeneratorContextManagerBasezBShared functionality for @contextmanager and @asynccontextmanager.c C sJ |||�| _ ||| | _| _| _t|dd �}|d kr@t| �j}|| _d S )Nr! )�genr* r( r) �getattr�typer! )r r* r( r) �docr r r �__init__Q s z%_GeneratorContextManagerBase.__init__N)r r r r! r2 r r r r r- N s r- c @ s( e Zd ZdZdd� Zdd� Zdd� ZdS ) �_GeneratorContextManagerz%Helper for @contextmanager decorator.c C s | � | j| j| j�S )N)� __class__r* r( r) )r r r r r' e s z%_GeneratorContextManager._recreate_cmc C s: | ` | `| `y t| j�S tk r4 td�d �Y nX d S )Nzgenerator didn't yield)r( r) r* �nextr. � StopIteration� RuntimeError)r r r r r k s z"_GeneratorContextManager.__enter__c C s� |d kr6yt | j� W n tk r* dS X td��n�|d krD|� }y| j�|||� W n� tk r~ } z||k S d }~X Y nf tk r� } z(||kr�dS |tkr�|j|kr�dS � W d d }~X Y n" t�� d |kr�dS � Y nX td��d S )NFzgenerator didn't stop� z#generator didn't stop after throw())r5 r. r6 r7 �throw� __cause__�sys�exc_info)r r0 �valuer �excr r r r t s. z!_GeneratorContextManager.__exit__N)r r r r! r' r r r r r r r3 ` s r3 c @ s e Zd ZdZdd� Zdd� ZdS )� _AsyncGeneratorContextManagerz Helper for @asynccontextmanager.c � s4 y| j �� I d H S tk r. td�d �Y nX d S )Nzgenerator didn't yield)r. � __anext__�StopAsyncIterationr7 )r r r r r% � s z(_AsyncGeneratorContextManager.__aenter__c � s |d kr<y| j �� I d H W n tk r0 d S X td��n�|d krJ|� }y"| j �|||�I d H td��W n� tk r� } z||k S d }~X Y nz tk r� } z.||kr�dS t|ttf�r�|j|kr�dS � W d d }~X Y n0 tk �r } z||k � r�� W d d }~X Y nX d S )Nzgenerator didn't stopz$generator didn't stop after athrow()F) r. r@ rA r7 �athrow� isinstancer6 r: � BaseException)r �typr= r r> r r r r& � s. z'_AsyncGeneratorContextManager.__aexit__N)r r r r! r% r& r r r r r? � s r? c s t � �� fdd��}|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)r3 )r( r) )r* r r �helper� s z contextmanager.<locals>.helper)r )r* rF r )r* r r � s c s t � �� fdd��}|S )a� @asynccontextmanager decorator. Typical usage: @asynccontextmanager async def some_async_generator(<arguments>): <setup> try: yield <value> finally: <cleanup> This makes this: async with some_async_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 rF s z#asynccontextmanager.<locals>.helper)r )r* rF r )r* r r � s c @ s( e Zd ZdZdd� Zdd� Zdd� ZdS ) 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 rG r r r r2 % s zclosing.__init__c C s | j S )N)rG )r r r r r ' s zclosing.__enter__c G s | j �� d S )N)rG �close)r r< r r r r ) s zclosing.__exit__N)r r r r! r2 r r r r r r r s c @ s( e Zd ZdZdd� Zdd� Zdd� ZdS )�_RedirectStreamNc C s || _ g | _d S )N)� _new_target� _old_targets)r � new_targetr r r r2 1 s z_RedirectStream.__init__c C s* | j �tt| j�� tt| j| j� | jS )N)rK �appendr/ r; �_stream�setattrrJ )r r r r r 6 s z_RedirectStream.__enter__c C s t t| j| j�� � d S )N)rO r; rN rK �pop)r �exctype�excinst�exctbr r r r ; s z_RedirectStream.__exit__)r r r rN r2 r r r r r r rI - s rI c @ s e Zd ZdZdZdS )r aA 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) �stdoutN)r r r r! rN r r r r r ? s c @ s e Zd ZdZdZdS )r zCContext manager for temporarily redirecting stderr to another file.�stderrN)r r r r! rN r r r r r O s c @ s( e Zd ZdZdd� Zdd� Zdd� ZdS ) 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 r2 ` s zsuppress.__init__c C s d S )Nr )r r r r r c s zsuppress.__enter__c C s |d k ot || j�S )N)� issubclassrV )r rQ rR rS r r r r f s zsuppress.__exit__N)r r r r! r2 r r r r r r r U s c @ sb e Zd ZdZedd� �Zedd� �Zdd� Zdd � Zd d � Z d d � Z dd� Z dd� Z ddd�Z dS )�_BaseExitStackz.A base class for ExitStack and AsyncExitStack.c s � �fdd�}|S )Nc s �� | ||�S )Nr )r r> �tb)�cm�cm_exitr r � _exit_wrapperx s z:_BaseExitStack._create_exit_wrapper.<locals>._exit_wrapperr )r[ r\ r] r )r[ r\ r �_create_exit_wrapperv s z#_BaseExitStack._create_exit_wrapperc s � ^�� � ��fdd�}|S )Nc s �� �� d S )Nr )r r> rZ )r( �callbackr) r r r] s z8_BaseExitStack._create_cb_wrapper.<locals>._exit_wrapperr )r( r) r] r )r( r_ r) r �_create_cb_wrapper| s z!_BaseExitStack._create_cb_wrapperc C s t � | _d S )N)r �_exit_callbacks)r r r r r2 � s z_BaseExitStack.__init__c C s t | �� }| j|_t� | _|S )z@Preserve the context stack by transferring it to a new instance.)r0 ra r )r � new_stackr r r �pop_all� s z_BaseExitStack.pop_allc C sB t |�}y |j}W n tk r0 | �|� Y nX | �||� |S )a Registers a callback with the standard __exit__ method signature. Can suppress exceptions the same way __exit__ method can. Also accepts any object with an __exit__ method (registering a call to the method instead of the object itself). )r0 r �AttributeError�_push_exit_callback� _push_cm_exit)r �exit�_cb_type� exit_methodr r r �push� s z_BaseExitStack.pushc C s( t |�}|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. )r0 r r rf )r r[ �_cm_type�_exit�resultr r r � enter_context� s z _BaseExitStack.enter_contextc O s| t | �dkr| ^}}} n>| s&td��n0d|krB|�d�}| ^}} ntdt | �d ��|j|f| �|�}||_|�|� |S )z\Registers an arbitrary callback and arguments. Cannot suppress exceptions. � zBdescriptor 'callback' of '_BaseExitStack' object needs an argumentr_ z8callback expected at least 1 positional argument, got %dr8 )�len� TypeErrorrP r` � __wrapped__re )r( r) r r_ r] r r r r_ � s z_BaseExitStack.callbackc C s" | � ||�}||_| �|d� dS )z;Helper to correctly register callbacks to __exit__ methods.TN)r^ �__self__re )r r[ r\ r] r r r rf � s z _BaseExitStack._push_cm_exitTc C s | j �||f� d S )N)ra rM )r r_ �is_syncr r r re � s z"_BaseExitStack._push_exit_callbackN)T)r r r r! � staticmethodr^ r` r2 rc rj rn r_ rf re r r r r rY s s rY c @ s( e Zd ZdZdd� Zdd� Zdd� ZdS ) 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 | S )Nr )r r r r r � s zExitStack.__enter__c s� |d d k }t �� d � � fdd�}d}d}xh| jr�| j�� \}}|sJt�y||� r`d}d}d}W q. t �� }||d |d � d}|}Y q.X q.W |r�y|d j} |d �W n tk r� | |d _� Y nX |o�|S )Nr r8 c s8 x,| j }||krd S |d ks$|� kr&P |} qW || _ 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< ra rP �AssertionErrorrv rD ) r � exc_details� received_excr{ �suppressed_exc� pending_raisert �cb�new_exc_details� fixed_ctxr )rz r r � s4 zExitStack.__exit__c C s | � ddd� dS )z%Immediately unwind the context stack.N)r )r r r r rH s zExitStack.closeN)r r r r! r r rH r r r r r � s 1c @ s` e Zd ZdZedd� �Zedd� �Zdd� Zdd � Zd d � Z d d � Z dd� Z dd� Z dd� Z dS )r a� Async context manager for dynamic management of a stack of exit callbacks. For example: async with AsyncExitStack() as stack: connections = [await stack.enter_async_context(get_connection()) for i in range(5)] # All opened connections will automatically be released at the # end of the async with statement, even if attempts to open a # connection later in the list raise an exception. c s � �fdd�}|S )Nc � s �� | ||�I d H S )Nr )r r> rZ )r[ r\ r r r] ' s z@AsyncExitStack._create_async_exit_wrapper.<locals>._exit_wrapperr )r[ r\ r] r )r[ r\ r �_create_async_exit_wrapper% s z)AsyncExitStack._create_async_exit_wrapperc s � ^�� � ��fdd�}|S )Nc � s �� ��I d H d S )Nr )r r> rZ )r( r_ r) r r r] . s z>AsyncExitStack._create_async_cb_wrapper.<locals>._exit_wrapperr )r( r) r] r )r( r_ r) r �_create_async_cb_wrapper+ s z'AsyncExitStack._create_async_cb_wrapperc � s. t |�}|j}|�|�I dH }| �||� |S )z�Enters the supplied async context manager. If successful, also pushes its __aexit__ method as a callback and returns the result of the __aenter__ method. N)r0 r& r% �_push_async_cm_exit)r r[ rk rl rm r r r �enter_async_context2 s z"AsyncExitStack.enter_async_contextc C sD t |�}y |j}W n tk r2 | �|d� Y nX | �||� |S )a# Registers a coroutine function with the standard __aexit__ method signature. Can suppress exceptions the same way __aexit__ method can. Also accepts any object with an __aexit__ method (registering a call to the method instead of the object itself). F)r0 r& rd re r� )r rg rh ri r r r �push_async_exit> s z AsyncExitStack.push_async_exitc O s~ t | �dkr| ^}}} n>| s&td��n0d|krB|�d�}| ^}} ntdt | �d ��|j|f| �|�}||_|�|d� |S )zfRegisters an arbitrary coroutine function and arguments. Cannot suppress exceptions. ro zMdescriptor 'push_async_callback' of 'AsyncExitStack' object needs an argumentr_ zCpush_async_callback expected at least 1 positional argument, got %dr8 F)rp rq rP r� rr re )r( r) r r_ r] r r r �push_async_callbackP s z"AsyncExitStack.push_async_callbackc � s | � ddd�I dH dS )z%Immediately unwind the context stack.N)r& )r r r r �aclosei s zAsyncExitStack.aclosec C s" | � ||�}||_| �|d� dS )zLHelper to correctly register coroutine function to __aexit__ method.FN)r� rs re )r r[ r\ r] r r r r� m s z"AsyncExitStack._push_async_cm_exitc � s | S )Nr )r r r r r% t s zAsyncExitStack.__aenter__c � s� |d d k }t �� d � � fdd�}d}d}xx| jr�| j�� \}}y0|rR||� }n||� I d H }|rpd}d}d}W q. t �� } || d |d � d}| }Y q.X q.W |r�y|d j} |d �W n tk r� | |d _� Y nX |o�|S )Nr r8 c s8 x,| j }||krd S |d ks$|� kr&P |} qW || _ d S )N)rv )rw rx ry )rz r r r{ } s z8AsyncExitStack.__aexit__.<locals>._fix_exception_contextFT)NNN)r; r< ra rP rv rD ) r r} r~ r{ r r� rt r� � cb_suppressr� r� r )rz r r& w s8 zAsyncExitStack.__aexit__N)r r r r! ru r� r� r� r� r� r� r� r% r& r r r r r s c @ s* e Zd ZdZd dd�Zdd� Zdd� ZdS ) r aO Context manager that does no additional processing. Used as a stand-in for a normal context manager, when a particular block of code is only sometimes used with a normal context manager: cm = optional_cm if condition else nullcontext() with cm: # Perform operation, using optional_cm if condition is True Nc C s || _ d S )N)� enter_result)r r� r r r r2 � s znullcontext.__init__c C s | j S )N)r� )r r r r r � s znullcontext.__enter__c G s d S )Nr )r �excinfor r r r � s znullcontext.__exit__)N)r r r r! r2 r r r r r r r � s ) r! r" r; r � collectionsr � functoolsr �__all__�ABCr r �objectr r- r3 r? r r r rI r r r rY r r r r r r r �<module> s< B -!! `E