Input hooks are a tool for inserting an external event loop into the prompt_toolkit event loop, so that the other loop can run as long as prompt_toolkit (actually asyncio) is idle. This is used in applications like IPython, so that GUI toolkits can display their windows while we wait at the prompt for user input.
As a consequence, we will “trampoline” back and forth between two event loops.
This will use a
SelectorEventLoop, not the :class:
ProactorEventLoop (on Windows) due to the way the
implementation works (contributions are welcome to make that work).
from prompt_toolkit.eventloop.inputhook import set_eventloop_with_inputhook def inputhook(inputhook_context): # At this point, we run the other loop. This loop is supposed to run # until either `inputhook_context.fileno` becomes ready for reading or # `inputhook_context.input_is_ready()` returns True. # A good way is to register this file descriptor in this other event # loop with a callback that stops this loop when this FD becomes ready. # There is no need to actually read anything from the FD. while True: ... set_eventloop_with_inputhook(inputhook) # Any asyncio code at this point will now use this new loop, with input # hook installed.