51 lines
1.2 KiB
Python
51 lines
1.2 KiB
Python
# spinner_await.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/538048.html
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# BEGIN SPINNER_AWAIT
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import asyncio
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import itertools
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import sys
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async def spin(msg): # <1>
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write, flush = sys.stdout.write, sys.stdout.flush
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for char in itertools.cycle('|/-\\'):
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status = char + ' ' + msg
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write(status)
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flush()
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write('\x08' * len(status))
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try:
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await asyncio.sleep(.1) # <3>
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except asyncio.CancelledError: # <4>
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break
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write(' ' * len(status) + '\x08' * len(status))
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async def slow_function(): # <5>
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# pretend waiting a long time for I/O
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await asyncio.sleep(3) # <6>
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return 42
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async def supervisor(): # <7>
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spinner = asyncio.ensure_future(spin('thinking!')) # <8>
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print('spinner object:', spinner) # <9>
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result = await slow_function() # <10>
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spinner.cancel() # <11>
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return result
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def main():
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loop = asyncio.get_event_loop() # <12>
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result = loop.run_until_complete(supervisor()) # <13>
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loop.close()
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print('Answer:', result)
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if __name__ == '__main__':
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main()
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# END SPINNER_AWAIT
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