40 lines
1.0 KiB
Python
40 lines
1.0 KiB
Python
# spinner_async_experiment.py
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# credits: Example by Luciano Ramalho inspired by
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# Michele Simionato's multiprocessing example in the python-list:
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# https://mail.python.org/pipermail/python-list/2009-February/675659.html
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import asyncio
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import itertools
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import time
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async def spin(msg: str) -> None:
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for char in itertools.cycle(r'\|/-'):
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status = f'\r{char} {msg}'
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print(status, flush=True, end='')
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try:
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await asyncio.sleep(.1)
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except asyncio.CancelledError:
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break
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print('THIS WILL NEVER BE OUTPUT')
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# tag::SPINNER_ASYNC_EXPERIMENT[]
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async def slow() -> int:
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time.sleep(3) # <4>
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return 42
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async def supervisor() -> int:
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spinner = asyncio.create_task(spin('thinking!')) # <1>
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print(f'spinner object: {spinner}') # <2>
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result = await slow() # <3>
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spinner.cancel() # <5>
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return result
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# end::SPINNER_ASYNC_EXPERIMENT[]
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def main() -> None:
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result = asyncio.run(supervisor())
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print(f'Answer: {result}')
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if __name__ == '__main__':
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main()
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