Low-level API Index¶
This page lists all low-level asyncio APIs.
Obtaining the Event Loop¶
| The preferred function to get the running event loop. | |
| Get an event loop instance (current or via the policy). | |
| Set the event loop as current via the current policy. | |
| Create a new event loop. | 
Examples
Event Loop Methods¶
See also the main documentation section about the event loop methods.
Lifecycle
| Run a Future/Task/awaitable until complete. | |
| Run the event loop forever. | |
| Stop the event loop. | |
| Close the event loop. | |
| Return  | |
| Return  | |
| Close asynchronous generators. | 
Debugging
| Enable or disable the debug mode. | |
| Get the current debug mode. | 
Scheduling Callbacks
| Invoke a callback soon. | |
| A thread-safe variant of  | |
| Invoke a callback after the given time. | |
| Invoke a callback at the given time. | 
Thread/Process Pool
| 
 | Run a CPU-bound or other blocking function in
a  | 
| Set the default executor for  | 
Tasks and Futures
| Create a  | |
| Schedule coroutine as a  | |
| Set a factory used by  | |
| Get the factory  | 
DNS
| 
 | Asynchronous version of  | 
| 
 | Asynchronous version of  | 
Networking and IPC
| 
 | Open a TCP connection. | 
| 
 | Create a TCP server. | 
| Open a Unix socket connection. | |
| Create a Unix socket server. | |
| Wrap a  | |
| Open a datagram (UDP) connection. | |
| 
 | Send a file over a transport. | 
| 
 | Upgrade an existing connection to TLS. | 
| 
 | Wrap a read end of a pipe into a  | 
| Wrap a write end of a pipe into a  | 
Sockets
| 
 | Receive data from the  | 
| 
 | Receive data from the  | 
| 
 | Send data to the  | 
| 
 | Connect the  | 
| 
 | Accept a  | 
| 
 | Send a file over the  | 
| Start watching a file descriptor for read availability. | |
| Stop watching a file descriptor for read availability. | |
| Start watching a file descriptor for write availability. | |
| Stop watching a file descriptor for write availability. | 
Unix Signals
| Add a handler for a  | |
| Remove a handler for a  | 
Subprocesses
| Spawn a subprocess. | |
| Spawn a subprocess from a shell command. | 
Error Handling
| Call the exception handler. | |
| Set a new exception handler. | |
| Get the current exception handler. | |
| The default exception handler implementation. | 
Examples
- Using - loop.create_connection()to implement an echo-client.
- Using - loop.create_connection()to connect a socket.
Transports¶
All transports implement the following methods:
| Close the transport. | |
| Return  | |
| Request for information about the transport. | |
| Set a new protocol. | |
| Return the current protocol. | 
Transports that can receive data (TCP and Unix connections,
pipes, etc).  Returned from methods like
loop.create_connection(), loop.create_unix_connection(),
loop.connect_read_pipe(), etc:
Read Transports
| Return  | |
| Pause receiving. | |
| Resume receiving. | 
Transports that can Send data (TCP and Unix connections,
pipes, etc).  Returned from methods like
loop.create_connection(), loop.create_unix_connection(),
loop.connect_write_pipe(), etc:
Write Transports
| Write data to the transport. | |
| Write buffers to the transport. | |
| Return  | |
| Close and send EOF after flushing buffered data. | |
| Close the transport immediately. | |
| Return high and low water marks for write flow control. | |
| Set new high and low water marks for write flow control. | 
Transports returned by loop.create_datagram_endpoint():
Datagram Transports
| Send data to the remote peer. | |
| Close the transport immediately. | 
Low-level transport abstraction over subprocesses.
Returned by loop.subprocess_exec() and
loop.subprocess_shell():
Subprocess Transports
| Return the subprocess process id. | |
| Return the transport for the requested communication pipe (stdin, stdout, or stderr). | |
| Return the subprocess return code. | |
| Kill the subprocess. | |
| Send a signal to the subprocess. | |
| Stop the subprocess. | |
| Kill the subprocess and close all pipes. | 
Protocols¶
Protocol classes can implement the following callback methods:
| 
 | Called when a connection is made. | 
| 
 | Called when the connection is lost or closed. | 
| 
 | Called when the transport’s buffer goes over the high water mark. | 
| 
 | Called when the transport’s buffer drains below the low water mark. | 
Streaming Protocols (TCP, Unix Sockets, Pipes)
| 
 | Called when some data is received. | 
| 
 | Called when an EOF is received. | 
Buffered Streaming Protocols
| 
 | Called to allocate a new receive buffer. | 
| 
 | Called when the buffer was updated with the received data. | 
| 
 | Called when an EOF is received. | 
Datagram Protocols
| 
 | Called when a datagram is received. | 
| 
 | Called when a previous send or receive operation raises an
 | 
Subprocess Protocols
| 
 | Called when the child process writes data into its stdout or stderr pipe. | 
| 
 | Called when one of the pipes communicating with the child process is closed. | 
| 
 | Called when the child process has exited. | 
Event Loop Policies¶
Policies is a low-level mechanism to alter the behavior of
functions like asyncio.get_event_loop().  See also
the main policies section for more
details.
Accessing Policies
| Return the current process-wide policy. | |
| Set a new process-wide policy. | |
| Base class for policy objects. | 
