← Back
Editing: contextlib.cpython-39.pyc
a XC?h0` � @ sZ d Z ddlZddlZddlZddlmZ ddlmZ ddlm Z m Z g d�Z G dd� dej �Z G d d � d ej �ZG d d � d e�ZG d d� d�ZG dd� dee e�ZG dd� dee�Zdd� Zdd� ZG dd� de �ZG dd� de �ZG dd � d e�ZG d d � d e�ZG d d � d e �ZG d!d"� d"�ZG d#d$� d$ee �Z G d%d&� d&ee�Z G d'd(� d(e �Z dS ))z4Utilities for with-statement contexts. See PEP 343.� N)�deque��wraps)� MethodType� GenericAlias) �asynccontextmanager�contextmanager�closing� nullcontext�AbstractContextManager�AbstractAsyncContextManager�AsyncExitStack�ContextDecorator� ExitStack�redirect_stdout�redirect_stderr�suppressc @ s: e Zd ZdZee�Zdd� Zej dd� �Z edd� �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/python39/lib64/python3.9/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 u rt�|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__� classmethodr �__class_getitem__r �abc�abstractmethodr r% r r r r r s r c @ s: e Zd ZdZee�Zdd� Zej dd� �Z edd� �Z dS ) r z9An abstract base class for asynchronous context managers.c � s | S r r r r r r � __aenter__+ s z&AbstractAsyncContextManager.__aenter__c � s dS r r r r r r � __aexit__/ s z%AbstractAsyncContextManager.__aexit__c C s | t u rt�|dd�S tS )Nr. r/ )r r r r! r" r r r r% 4 s �z,AbstractAsyncContextManager.__subclasshook__N) r& r' r( r) r* r r+ r. r, r- r/ r% r r r r r % s r 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: �� � � � | i |��W d � S 1 s,0 Y d S �N)r0 ��args�kwds��funcr r r �innerL s z(ContextDecorator.__call__.<locals>.innerr )r r6 r7 r r5 r �__call__K s zContextDecorator.__call__N)r& r' r( r) r0 r8 r r r r r < s r c @ s e Zd ZdZdd� Zdd� ZdS )� _GeneratorContextManagerBasezBShared functionality for @contextmanager and @asynccontextmanager.c C sN ||i |��| _ ||| | _| _| _t|dd �}|d u rDt| �j}|| _d S )Nr) )�genr6 r3 r4 �getattr�typer) )r r6 r3 r4 �docr r r �__init__V s z%_GeneratorContextManagerBase.__init__c C s | � | j| j| j�S r1 )� __class__r6 r3 r4 r r r r r0 d s z)_GeneratorContextManagerBase._recreate_cmN)r& r' r( r) r> r0 r r r r r9 S s r9 c @ s e Zd ZdZdd� Zdd� ZdS )�_GeneratorContextManagerz%Helper for @contextmanager decorator.c C s: | ` | `| `z t| j�W S ty4 td�d �Y n0 d S �Nzgenerator didn't yield)r3 r4 r6 �nextr: � StopIteration� RuntimeErrorr r r r r r s z"_GeneratorContextManager.__enter__c C s |d u r6zt | j� W n ty* Y dS 0 td��n�|d u rD|� }z| j�|||� W n� ty� } z||uW Y d }~S d }~0 ty� } zF||u r�W Y d }~dS t|t�r�|j|u r�W Y d }~dS � W Y d }~n<d }~0 t�y } z||u� r�� W Y d }~dS d }~0 0 td��d S )NF�generator didn't stopz#generator didn't stop after throw())rB r: rC rD �throw� isinstance� __cause__� BaseException�r �typ�valuer �excr r r r { s4 �� z!_GeneratorContextManager.__exit__N)r& r' r( r) r r r r r r r@ k s r@ c @ s e Zd ZdZdd� Zdd� ZdS )� _AsyncGeneratorContextManagerz*Helper for @asynccontextmanager decorator.c � s@ | ` | `| `z| j�� I d H W S ty: td�d �Y n0 d S rA )r3 r4 r6 r: � __anext__�StopAsyncIterationrD r r r r r. � s z(_AsyncGeneratorContextManager.__aenter__c � s4 |d u r>z| j �� I d H W n ty0 Y dS 0 td��� n�|d u rL|� }z| j �|||�I d H W n� ty� } z||uW Y d }~S d }~0 t� y� } zJ||u r�W Y d }~dS t|ttf�r�|j|u r�W Y d }~dS � W Y d }~n<d }~0 t�y& } z||u�r� W Y d }~dS d }~0 0 td��d S )NFrE z$generator didn't stop after athrow()) r: rO rP rD �athrowrG rC rH rI rJ r r r r/ � s4 �� z'_AsyncGeneratorContextManager.__aexit__N)r& r' r( r) r. r/ r r r r rN � s rN 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 r1 )r@ r2 �r6 r r �helper s z contextmanager.<locals>.helperr �r6 rS r rR r r � s r 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 r1 )rN r2 rR r r rS & s z#asynccontextmanager.<locals>.helperr rT r rR r r s r 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 r1 ��thing)r rV r r r r> = s zclosing.__init__c C s | j S r1 rU r r r r r ? s zclosing.__enter__c G s | j �� d S r1 )rV �close)r �exc_infor r r r A s zclosing.__exit__N�r& r' r( r) r> r r r r r r r , s r c @ s( e Zd ZdZdd� Zdd� Zdd� ZdS )�_RedirectStreamNc C s || _ g | _d S r1 )� _new_target� _old_targets)r � new_targetr r r r> I s z_RedirectStream.__init__c C s* | j �tt| j�� tt| j| j� | jS r1 )r\ �appendr; �sys�_stream�setattrr[ r r r r r N s z_RedirectStream.__enter__c C s t t| j| j�� � d S r1 )ra r_ r` r\ �pop�r �exctype�excinst�exctbr r r r S s z_RedirectStream.__exit__)r& r' r( r` r> r r r r r r rZ E s rZ 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) r` r r r r r W s r c @ s e Zd ZdZdZdS )r zCContext manager for temporarily redirecting stderr to another file.�stderrNrh r r r r r g s r 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 r1 )� _exceptions)r � exceptionsr r r r> x s zsuppress.__init__c C s d S r1 r r r r r r { s zsuppress.__enter__c C s |d uot || j�S r1 )� issubclassrj rc r r r r ~ s zsuppress.__exit__NrY r r r r r m s r 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 C s t || �S r1 �r ��cm�cm_exitr r r �_create_exit_wrapper� s z#_BaseExitStack._create_exit_wrapperc s � ��fdd�}|S )Nc s �� i ��� d S r1 r �r rM �tb�r3 �callbackr4 r r � _exit_wrapper� s z8_BaseExitStack._create_cb_wrapper.<locals>._exit_wrapperr �rv r3 r4 rw r ru r �_create_cb_wrapper� s z!_BaseExitStack._create_cb_wrapperc C s t � | _d S r1 )r �_exit_callbacksr r r r r> � s z_BaseExitStack.__init__c C s t | �� }| j|_t� | _|S )z@Preserve the context stack by transferring it to a new instance.)r< rz r )r � new_stackr r r �pop_all� s z_BaseExitStack.pop_allc C s@ t |�}z |j}W n ty. | �|� Y n0 | �||� |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). )r< 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. )r< r r r �r rp �_cm_type�_exit�resultr r r � enter_context� s z _BaseExitStack.enter_contextc O s, | j |g|�R i |��}||_| �|� |S )z\Registers an arbitrary callback and arguments. Cannot suppress exceptions. )ry � __wrapped__r~ �r rv r3 r4 rw r r r rv � s z_BaseExitStack.callbackc C s | � ||�}| �|d� dS )z;Helper to correctly register callbacks to __exit__ methods.TN)rr r~ �r rp rq rw r r r r � s z _BaseExitStack._push_cm_exitTc C s | j �||f� d S r1 )rz r^ )r rv �is_syncr r r r~ � s z"_BaseExitStack._push_exit_callbackN)T)r& r' r( r) � staticmethodrr ry r> r| r� r� rv r r~ r r r r rm � s rm 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 r1 r r r r r r � s zExitStack.__enter__c s� |d d u}t �� d � � fdd�}d}d}| jr�| j�� \}}|sHJ �z||� r^d}d}d}W q, t �� }||d |d � d}|}Y q,0 q,|r�z|d j} |d �W n ty� | |d _� Y n0 |o�|S )Nr � c s4 | j }|d u s||u rd S |� u r$q*|} q || _ d S r1 �� __context__��new_exc�old_exc� exc_context�� frame_excr r �_fix_exception_context� s z2ExitStack.__exit__.<locals>._fix_exception_contextFT�NNN�r_ rX rz rb r� rI ) r � exc_details� received_excr� �suppressed_exc� pending_raiser� �cb�new_exc_details� fixed_ctxr r� r r � s4 zExitStack.__exit__c C s | � ddd� dS �z%Immediately unwind the context stack.N)r r r r r rW s zExitStack.closeN)r& r' r( r) r r rW r r r r r � s 1r c @ 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 C s t || �S r1 rn ro r r r �_create_async_exit_wrapper- s z)AsyncExitStack._create_async_exit_wrapperc s � ��fdd�}|S )Nc � s �� i ���I d H d S r1 r rs ru r r rw 3 s z>AsyncExitStack._create_async_cb_wrapper.<locals>._exit_wrapperr rx r ru r �_create_async_cb_wrapper1 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)r< r/ r. �_push_async_cm_exitr� r r r �enter_async_context7 s z"AsyncExitStack.enter_async_contextc C sB t |�}z |j}W n ty0 | �|d� Y n0 | �||� |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)r< r/ r} r~ r� r� r r r �push_async_exitC s z AsyncExitStack.push_async_exitc O s. | j |g|�R i |��}||_| �|d� |S )zfRegisters an arbitrary coroutine function and arguments. Cannot suppress exceptions. F)r� r� r~ r� r r r �push_async_callbackU s z"AsyncExitStack.push_async_callbackc � s | � ddd�I dH dS r� )r/ r r r r �acloseb s zAsyncExitStack.aclosec C s | � ||�}| �|d� dS )zLHelper to correctly register coroutine function to __aexit__ method.FN)r� r~ r� r r r r� f s z"AsyncExitStack._push_async_cm_exitc � s | S r1 r r r r r r. l s zAsyncExitStack.__aenter__c � s� |d d u}t �� d � � fdd�}d}d}| jr�| j�� \}}z0|rP||� }n||� I d H }|rnd}d}d}W q, t �� } || d |d � d}| }Y q,0 q,|r�z|d j} |d �W n ty� | |d _� Y n0 |o�|S )Nr r� c s4 | j }|d u s||u rd S |� u r$q*|} q || _ d S r1 r� r� r� r r r� u s z8AsyncExitStack.__aexit__.<locals>._fix_exception_contextFTr� r� ) r r� r� r� r� r� r� r� � cb_suppressr� r� r r� r r/ o s8 zAsyncExitStack.__aexit__N)r& r' r( r) r� r� r� r� r� r� r� r� r. r/ r r r r r s r 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 r1 �� enter_result)r r� r r r r> � s znullcontext.__init__c C s | j S r1 r� r r r r r � s znullcontext.__enter__c G s d S r1 r )r �excinfor r r r � s znullcontext.__exit__)NrY r r r r r � s r ) r) r, r_ r � collectionsr � functoolsr �typesr r �__all__�ABCr r �objectr r9 r@ rN r r r rZ r r r rm r r r r r r r �<module> s> �A �>!! PE
Save File
Cancel