Polling the keyboard (detect a keypress) in python

Asked 2008-11-15T03:29:09.777

How can I poll the keyboard from a console python app? Specifically, I would like to do something akin to this in the midst of a lot of other I/O activities (socket selects, serial port access, etc.):

while True:
    # doing amazing pythonic embedded stuff
    # ...

    # periodically do a non-blocking check to see if
    # we are being told to do something else
    x = keyboard.read(1000, timeout = 0)

    if len(x):
        # ok, some key got pressed
        # do something

What is the correct pythonic way to do this on Windows? Also, portability to Linux wouldn't be bad, though it's not required.

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2 Answers

The standard approach is to use the select module.

However, this doesn't work on Windows. For that, you can use the msvcrt module's keyboard polling.

Often, this is done with multiple threads -- one per device being "watched" plus the background processes that might need to be interrupted by the device.

answered 2008-11-15T17:09:00.650

import sys
import select

def heardEnter():
    i,o,e = select.select([sys.stdin],[],[],0.0001)
    for s in i:
        if s == sys.stdin:
            input = sys.stdin.readline()
            return True
    return False

answered 2009-09-20T01:47:23.303

Polling the keyboard (detect a keypress) in python

2 Answers

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