59 lines
1.4 KiB
Python
59 lines
1.4 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 math
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# tag::SPINNER_ASYNC_NAP[]
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async def is_prime(n):
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if n < 2:
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return False
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if n == 2:
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return True
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if n % 2 == 0:
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return False
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sleep = asyncio.sleep # <1>
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root = int(math.floor(math.sqrt(n)))
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for i in range(3, root + 1, 2):
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if n % i == 0:
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return False
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if i % 100_000 == 1: # <2>
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await sleep(0)
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return True
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# end::SPINNER_ASYNC_NAP[]
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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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blanks = ' ' * len(status)
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print(f'\r{blanks}\r', end='')
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async def slow() -> int:
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await is_prime(5_000_111_000_222_021) # <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('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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def main() -> None:
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result = asyncio.run(supervisor())
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print('Answer:', result)
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if __name__ == '__main__':
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main()
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