Issue #23049:  Pure python equivalent shouldn't imply more exactitude than is really there.

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branch : 3.4
Issue #23070: Fix a comment in the tutorial.

"Python" has 6 characters, not 7.

Reported by Ross Burnett.

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branch : 3.4
Issue #23074: asyncio.get_event_loop() now raises an exception if the thread
has no event loop even if assertions are disabled.

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branch : 3.4