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asyncio

asyncio.events

Event loop and event loop policy.

Classes

AbstractEventLoop

Abstract event loop.
add_reader(self, fd, callback, *args)
add_signal_handler(self, sig, callback, *args)
add_writer(self, fd, callback, *args)
call_at(self, when, callback, *args, context=None)
call_exception_handler(self, context)
call_later(self, delay, callback, *args, context=None)
call_soon(self, callback, *args, context=None)
call_soon_threadsafe(self, callback, *args, context=None)
close(self)

  Close the loop.

          The loop should not be running.

          This is idempotent and irreversible.

          No other methods should be called after this one.
        
connect_accepted_socket(self, protocol_factory, sock, *, ssl=None, ssl_handshake_timeout=None)

  Handle an accepted connection.

          This is used by servers that accept connections outside of
          asyncio, but use asyncio to handle connections.

          This method is a coroutine.  When completed, the coroutine
          returns a (transport, protocol) pair.
        
connect_read_pipe(self, protocol_factory, pipe)

  Register read pipe in event loop. Set the pipe to non-blocking mode.

          protocol_factory should instantiate object with Protocol interface.
          pipe is a file-like object.
          Return pair (transport, protocol), where transport supports the
          ReadTransport interface.
connect_write_pipe(self, protocol_factory, pipe)

  Register write pipe in event loop.

          protocol_factory should instantiate object with BaseProtocol interface.
          Pipe is file-like object already switched to nonblocking.
          Return pair (transport, protocol), where transport support
          WriteTransport interface.
create_connection(self, protocol_factory, host=None, port=None, *, ssl=None, family=0, proto=0, flags=0, sock=None, local_addr=None, server_hostname=None, ssl_handshake_timeout=None, happy_eyeballs_delay=None, interleave=None)
create_datagram_endpoint(self, protocol_factory, local_addr=None, remote_addr=None, *, family=0, proto=0, flags=0, reuse_address=None, reuse_port=None, allow_broadcast=None, sock=None)

  A coroutine which creates a datagram endpoint.

          This method will try to establish the endpoint in the background.
          When successful, the coroutine returns a (transport, protocol) pair.

          protocol_factory must be a callable returning a protocol instance.

          socket family AF_INET, socket.AF_INET6 or socket.AF_UNIX depending on
          host (or family if specified), socket type SOCK_DGRAM.

          reuse_address tells the kernel to reuse a local socket in
          TIME_WAIT state, without waiting for its natural timeout to
          expire. If not specified it will automatically be set to True on
          UNIX.

          reuse_port tells the kernel to allow this endpoint to be bound to
          the same port as other existing endpoints are bound to, so long as
          they all set this flag when being created. This option is not
          supported on Windows and some UNIX's. If the
          :py:data:`~socket.SO_REUSEPORT` constant is not defined then this
          capability is unsupported.

          allow_broadcast tells the kernel to allow this endpoint to send
          messages to the broadcast address.

          sock can optionally be specified in order to use a preexisting
          socket object.
        
create_future(self)
create_server(self, protocol_factory, host=None, port=None, *, family=<AddressFamily.AF_UNSPEC: 0>, flags=<AddressInfo.AI_PASSIVE: 1>, sock=None, backlog=100, ssl=None, reuse_address=None, reuse_port=None, ssl_handshake_timeout=None, start_serving=True)

  A coroutine which creates a TCP server bound to host and port.

          The return value is a Server object which can be used to stop
          the service.

          If host is an empty string or None all interfaces are assumed
          and a list of multiple sockets will be returned (most likely
          one for IPv4 and another one for IPv6). The host parameter can also be
          a sequence (e.g. list) of hosts to bind to.

          family can be set to either AF_INET or AF_INET6 to force the
          socket to use IPv4 or IPv6. If not set it will be determined
          from host (defaults to AF_UNSPEC).

          flags is a bitmask for getaddrinfo().

          sock can optionally be specified in order to use a preexisting
          socket object.

          backlog is the maximum number of queued connections passed to
          listen() (defaults to 100).

          ssl can be set to an SSLContext to enable SSL over the
          accepted connections.

          reuse_address tells the kernel to reuse a local socket in
          TIME_WAIT state, without waiting for its natural timeout to
          expire. If not specified will automatically be set to True on
          UNIX.

          reuse_port tells the kernel to allow this endpoint to be bound to
          the same port as other existing endpoints are bound to, so long as
          they all set this flag when being created. This option is not
          supported on Windows.

          ssl_handshake_timeout is the time in seconds that an SSL server
          will wait for completion of the SSL handshake before aborting the
          connection. Default is 60s.

          start_serving set to True (default) causes the created server
          to start accepting connections immediately.  When set to False,
          the user should await Server.start_serving() or Server.serve_forever()
          to make the server to start accepting connections.
        
create_task(self, coro, *, name=None)
create_unix_connection(self, protocol_factory, path=None, *, ssl=None, sock=None, server_hostname=None, ssl_handshake_timeout=None)
create_unix_server(self, protocol_factory, path=None, *, sock=None, backlog=100, ssl=None, ssl_handshake_timeout=None, start_serving=True)

  A coroutine which creates a UNIX Domain Socket server.

          The return value is a Server object, which can be used to stop
          the service.

          path is a str, representing a file system path to bind the
          server socket to.

          sock can optionally be specified in order to use a preexisting
          socket object.

          backlog is the maximum number of queued connections passed to
          listen() (defaults to 100).

          ssl can be set to an SSLContext to enable SSL over the
          accepted connections.

          ssl_handshake_timeout is the time in seconds that an SSL server
          will wait for the SSL handshake to complete (defaults to 60s).

          start_serving set to True (default) causes the created server
          to start accepting connections immediately.  When set to False,
          the user should await Server.start_serving() or Server.serve_forever()
          to make the server to start accepting connections.
        
default_exception_handler(self, context)
get_debug(self)
get_exception_handler(self)
get_task_factory(self)
getaddrinfo(self, host, port, *, family=0, type=0, proto=0, flags=0)
getnameinfo(self, sockaddr, flags=0)
is_closed(self)

  Returns True if the event loop was closed.
is_running(self)

  Return whether the event loop is currently running.
remove_reader(self, fd)
remove_signal_handler(self, sig)
remove_writer(self, fd)
run_forever(self)

  Run the event loop until stop() is called.
run_in_executor(self, executor, func, *args)
run_until_complete(self, future)

  Run the event loop until a Future is done.

          Return the Future's result, or raise its exception.
        
sendfile(self, transport, file, offset=0, count=None, *, fallback=True)

  Send a file through a transport.

          Return an amount of sent bytes.
        
set_debug(self, enabled)
set_default_executor(self, executor)
set_exception_handler(self, handler)
set_task_factory(self, factory)
shutdown_asyncgens(self)

  Shutdown all active asynchronous generators.
shutdown_default_executor(self)

  Schedule the shutdown of the default executor.
sock_accept(self, sock)
sock_connect(self, sock, address)
sock_recv(self, sock, nbytes)
sock_recv_into(self, sock, buf)
sock_sendall(self, sock, data)
sock_sendfile(self, sock, file, offset=0, count=None, *, fallback=None)
start_tls(self, transport, protocol, sslcontext, *, server_side=False, server_hostname=None, ssl_handshake_timeout=None)

  Upgrade a transport to TLS.

          Return a new transport that *protocol* should start using
          immediately.
        
stop(self)

  Stop the event loop as soon as reasonable.

          Exactly how soon that is may depend on the implementation, but
          no more I/O callbacks should be scheduled.
        
subprocess_exec(self, protocol_factory, *args, stdin=-1, stdout=-1, stderr=-1, **kwargs)
subprocess_shell(self, protocol_factory, cmd, *, stdin=-1, stdout=-1, stderr=-1, **kwargs)
time(self)

AbstractEventLoopPolicy

Abstract policy for accessing the event loop.
get_child_watcher(self)

  Get the watcher for child processes.
get_event_loop(self)

  Get the event loop for the current context.

          Returns an event loop object implementing the BaseEventLoop interface,
          or raises an exception in case no event loop has been set for the
          current context and the current policy does not specify to create one.

          It should never return None.
new_event_loop(self)

  Create and return a new event loop object according to this
          policy's rules. If there's need to set this loop as the event loop for
          the current context, set_event_loop must be called explicitly.
set_child_watcher(self, watcher)

  Set the watcher for child processes.
set_event_loop(self, loop)

  Set the event loop for the current context to loop.

AbstractServer

Abstract server returned by create_server().
close(self)

  Stop serving.  This leaves existing connections open.
get_loop(self)

  Get the event loop the Server object is attached to.
is_serving(self)

  Return True if the server is accepting connections.
serve_forever(self)

  Start accepting connections until the coroutine is cancelled.

          The server is closed when the coroutine is cancelled.
        
start_serving(self)

  Start accepting connections.

          This method is idempotent, so it can be called when
          the server is already being serving.
        
wait_closed(self)

  Coroutine to wait until service is closed.

BaseDefaultEventLoopPolicy

Default policy implementation for accessing the event loop.

    In this policy, each thread has its own event loop.  However, we
    only automatically create an event loop by default for the main
    thread; other threads by default have no event loop.

    Other policies may have different rules (e.g. a single global
    event loop, or automatically creating an event loop per thread, or
    using some other notion of context to which an event loop is
    associated).
    
get_child_watcher(self)

  Get the watcher for child processes.
get_event_loop(self)

  Get the event loop for the current context.

          Returns an instance of EventLoop or raises an exception.
        
new_event_loop(self)

  Create a new event loop.

          You must call set_event_loop() to make this the current event
          loop.
        
set_child_watcher(self, watcher)

  Set the watcher for child processes.
set_event_loop(self, loop)

  Set the event loop.

Handle

Object returned by callback registration methods.
cancel(self)
cancelled(self)

TimerHandle

Object returned by timed callback registration methods.
cancel(self)
cancelled(self)
when(self)

  Return a scheduled callback time.

          The time is an absolute timestamp, using the same time
          reference as loop.time().
        

Functions

get_child_watcher

get_child_watcher()

  Equivalent to calling get_event_loop_policy().get_child_watcher().

get_event_loop

get_event_loop()

  Return an asyncio event loop.

  When called from a coroutine or a callback (e.g. scheduled with
  call_soon or similar API), this function will always return the
  running event loop.

  If there is no running event loop set, the function will return
  the result of `get_event_loop_policy().get_event_loop()` call.

get_event_loop_policy

get_event_loop_policy()

  Get the current event loop policy.

get_running_loop

get_running_loop()

  Return the running event loop.  Raise a RuntimeError if there is none.

  This function is thread-specific.

new_event_loop

new_event_loop()

  Equivalent to calling get_event_loop_policy().new_event_loop().

set_child_watcher

set_child_watcher(watcher)

  Equivalent to calling
      get_event_loop_policy().set_child_watcher(watcher).

set_event_loop

set_event_loop(loop)

  Equivalent to calling get_event_loop_policy().set_event_loop(loop).

set_event_loop_policy

set_event_loop_policy(policy)

  Set the current event loop policy.

      If policy is None, the default policy is restored.

Modules

contextvars

format_helpers

os

socket

subprocess

sys

threading