It's unfortunately not so easy to do that. If you're trying to make some sort of text user interface, you may want to look into curses. If you want to display things like you normally would in a terminal, but want input like that, then you'll have to work with termios, which unfortunately appears to be poorly documented in Python. Neither of these options are that simple, though, unfortunately. Additionally, they do not work under Windows; if you need them to work under Windows, you'll have to use PDCurses as a replacement for curses or pywin32 rather than termios.
I was able to get this working decently. It prints out the hexadecimal representation of keys you type. As I said in the comments of your question, arrows are tricky; I think you'll agree.
#!/usr/bin/env python
import sys
import termios
import contextlib
@contextlib.contextmanager
def raw_mode(file):
old_attrs = termios.tcgetattr(file.fileno())
new_attrs = old_attrs[:]
new_attrs[3] = new_attrs[3] & ~(termios.ECHO | termios.ICANON)
try:
termios.tcsetattr(file.fileno(), termios.TCSADRAIN, new_attrs)
yield
finally:
termios.tcsetattr(file.fileno(), termios.TCSADRAIN, old_attrs)
def main():
print 'exit with ^C or ^D'
with raw_mode(sys.stdin):
try:
while True:
ch = sys.stdin.read(1)
if not ch or ch == chr(4):
break
print '%02x' % ord(ch),
except (KeyboardInterrupt, EOFError):
pass
if __name__ == '__main__':
main()
I was searching for a simple solution without window focus. Jayk's answer, pynput, works perfect for me. Here is the example how I use it.
from pynput import keyboard
def on_press(key):
if key == keyboard.Key.esc:
return False # stop listener
try:
k = key.char # single-char keys
except:
k = key.name # other keys
if k in ['1', '2', 'left', 'right']: # keys of interest
# self.keys.append(k) # store it in global-like variable
print('Key pressed: ' + k)
return False # stop listener; remove this if want more keys
listener = keyboard.Listener(on_press=on_press)
listener.start() # start to listen on a separate thread
listener.join() # remove if main thread is polling self.keys
There is a way to do key listeners in python. This functionality is available through pynput.
Command line:
$ pip install pynput
Python code:
from pynput import keyboard
# your code here
Here's how can do it on Windows:
"""
Display series of numbers in infinite loop
Listen to key "s" to stop
Only works on Windows because listening to keys
is platform dependent
"""
# msvcrt is a windows specific native module
import msvcrt
import time
# asks whether a key has been acquired
def kbfunc():
#this is boolean for whether the keyboard has bene hit
x = msvcrt.kbhit()
if x:
#getch acquires the character encoded in binary ASCII
ret = msvcrt.getch()
else:
ret = False
return ret
#begin the counter
number = 1
#infinite loop
while True:
#acquire the keyboard hit if exists
x = kbfunc()
#if we got a keyboard hit
if x != False and x.decode() == 's':
#we got the key!
#because x is a binary, we need to decode to string
#use the decode() which is part of the binary object
#by default, decodes via utf8
#concatenation auto adds a space in between
print ("STOPPING, KEY:", x.decode())
#break loop
break
else:
#prints the number
print (number)
#increment, there's no ++ in python
number += 1
#wait half a second
time.sleep(0.5)
sudo pip install keyboardTake full control of your keyboard with this small Python library. Hook global events, register hotkeys, simulate key presses and much more.
Global event hook on all keyboards (captures keys regardless of focus). Listen and sends keyboard events. Works with Windows and Linux (requires sudo), with experimental OS X support (thanks @glitchassassin!). Pure Python, no C modules to be compiled. Zero dependencies. Trivial to install and deploy, just copy the files. Python 2 and 3. Complex hotkey support (e.g. Ctrl+Shift+M, Ctrl+Space) with controllable timeout. Includes high level API (e.g. record and play, add_abbreviation). Maps keys as they actually are in your layout, with full internationalization support (e.g. Ctrl+ç). Events automatically captured in separate thread, doesn't block main program. Tested and documented. Doesn't break accented dead keys (I'm looking at you, pyHook). Mouse support available via project mouse (pip install mouse).
From README.md:
import keyboard
keyboard.press_and_release('shift+s, space')
keyboard.write('The quick brown fox jumps over the lazy dog.')
# Press PAGE UP then PAGE DOWN to type "foobar".
keyboard.add_hotkey('page up, page down', lambda: keyboard.write('foobar'))
# Blocks until you press esc.
keyboard.wait('esc')
# Record events until 'esc' is pressed.
recorded = keyboard.record(until='esc')
# Then replay back at three times the speed.
keyboard.play(recorded, speed_factor=3)
# Type @@ then press space to replace with abbreviation.
keyboard.add_abbreviation('@@', '[email protected]')
# Block forever.
keyboard.wait()
Although I like using the keyboard module to capture keyboard events, I don't like its record() function because it returns an array like [KeyboardEvent("A"), KeyboardEvent("~")], which I find kind of hard to read. So, to record keyboard events, I like to use the keyboard module and the threading module simultaneously, like this:
import keyboard
import string
from threading import *
# I can't find a complete list of keyboard keys, so this will have to do:
keys = list(string.ascii_lowercase)
"""
Optional code(extra keys):
keys.append("space_bar")
keys.append("backspace")
keys.append("shift")
keys.append("esc")
"""
def listen(key):
while True:
keyboard.wait(key)
print("[+] Pressed",key)
threads = [Thread(target=listen, kwargs={"key":key}) for key in keys]
for thread in threads:
thread.start()
/dev/input/*and extract keypresses directly. – Blender