67 lines
1.6 KiB
Python
67 lines
1.6 KiB
Python
"""
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Coroutine closing demonstration::
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# BEGIN DEMO_CORO_EXC_1
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>>> exc_coro = demo_exc_handling()
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>>> next(exc_coro)
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-> coroutine started
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>>> exc_coro.send(11)
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-> coroutine received: 11
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>>> exc_coro.send(22)
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-> coroutine received: 22
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>>> exc_coro.close()
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>>> from inspect import getgeneratorstate
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>>> getgeneratorstate(exc_coro)
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'GEN_CLOSED'
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# END DEMO_CORO_EXC_1
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Coroutine handling exception::
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# BEGIN DEMO_CORO_EXC_2
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>>> exc_coro = demo_exc_handling()
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>>> next(exc_coro)
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-> coroutine started
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>>> exc_coro.send(11)
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-> coroutine received: 11
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>>> exc_coro.throw(DemoException)
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*** DemoException handled. Continuing...
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>>> getgeneratorstate(exc_coro)
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'GEN_SUSPENDED'
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# END DEMO_CORO_EXC_2
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Coroutine not handling exception::
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# BEGIN DEMO_CORO_EXC_3
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>>> exc_coro = demo_exc_handling()
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>>> next(exc_coro)
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-> coroutine started
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>>> exc_coro.send(11)
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-> coroutine received: 11
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>>> exc_coro.throw(ZeroDivisionError)
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Traceback (most recent call last):
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...
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ZeroDivisionError
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>>> getgeneratorstate(exc_coro)
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'GEN_CLOSED'
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# END DEMO_CORO_EXC_3
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"""
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# BEGIN EX_CORO_EXC
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class DemoException(Exception):
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"""An exception type for the demonstration."""
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def demo_exc_handling():
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print('-> coroutine started')
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while True:
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try:
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x = yield
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except DemoException: # <1>
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print('*** DemoException handled. Continuing...')
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else: # <2>
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print('-> coroutine received: {!r}'.format(x))
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raise RuntimeError('This line should never run.') # <3>
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# END EX_CORO_EXC
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