[Tutor] key detection

[Alex Kleider]

On 2015-05-05 15:36, Alan Gauld wrote:
> On 05/05/15 22:30, Jim Mooney Py3.4.3winXP wrote:
>> Can python detect a keypress?

The following works for my (on my Ubuntu platform) system
although probably won't be of much use on a Redmond OS.

#!/usr/bin/env python3
# file: 'readchar.py'
"""
Provides readchar()
Implementation of a way to get a single character of input
without waiting for the user to hit <Enter>.
(OS is Linux, Ubuntu 14.04)
"""

import tty, sys, termios

class ReadChar():
     def __enter__(self):
         self.fd = sys.stdin.fileno()
         self.old_settings = termios.tcgetattr(self.fd)
         tty.setraw(sys.stdin.fileno())
         return sys.stdin.read(1)
     def __exit__(self, type, value, traceback):
         termios.tcsetattr(self.fd, termios.TCSADRAIN, self.old_settings)

def readchar():
     with ReadChar() as rc:
         return rc

def testrc():
     print\
     ("Testing ReadChar: enter a character and we'll report what it is.")
     while True:
         char = readchar()
         if ord(char) <= 32:
             print("You entered character with ordinal {}, aka {}."
                         .format(ord(char), repr(char)))
         else:
             print("You entered character '{}'."
                         .format(char))
         if char in "^C^D":
             break

if __name__ == "__main__":
     testrc()

To give credit where credit is due: I seem to remember cobbling this 
together
based on something that was discussed on this mailing list quite some 
time ago.
i.e. it's not original work:-)