Asyncio is part of the Python standard library, providing an event-loop-based asynchronous programming method that can be used to write efficient concurrent programs. asyncio mainly has the following uses:
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Asynchronous I/O operations: Asynchronous I/O operations are one of the most common applications of asyncio. It can be used to handle I/O-intensive tasks such as network communication, database operations, and file reading and writing to improve the throughput and responsiveness of the program.
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Coroutine: asyncio provides an asynchronous programming method based on coroutine. Coroutine is a lightweight thread that can execute multiple tasks concurrently under a single thread.
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Task scheduling: asyncio provides a task scheduling mechanism that enables different coroutines to be executed at different times, thereby realizing the writing of asynchronous logic.
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Cancellable tasks: asyncio supports canceling tasks, which can stop the current task without blocking other tasks.
Commonly used APIs are:
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asyncio.get_event_loop(): Get the event loop object of the current thread.
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asyncio.ensure_future(): Wrap ordinary functions into coroutine objects and submit them to the event loop for execution.
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asyncio.sleep(): Simulate the waiting time of asynchronous IO operations.
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asyncio.wait(): Wait for a set of coroutines to complete.
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asyncio.gather(): Wait for multiple coroutines to complete at the same time in one coroutine, and get their execution results.
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asyncio.create_task(): Create a task and submit it to the event loop for execution.
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asyncio.run(): Execute a coroutine in a new event loop and close the event loop.
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asyncio.CancelledError: Identifies the exception type that the task was canceled.
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asyncio.Queue: Provides a thread-safe queue for data exchange between coroutines.
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asyncio.StreamReader/StreamWriter: Provides the abstraction of asynchronous I/O operations, used to implement operations such as network communication in coroutines.