curses_keypress.py

# this works quite nicely in a terminal, and can be more easily extended

from curses import wrapper

def main(stdscr):
    ch = ''
    while ch != 'q':
        # getch returns codepoint, so convert to chr
        # this makes things like [Left] behave strangely - if you want to
        # capture those, don't call chr but instead look at which number is
        # produced by the key and test against that
        ch = chr(stdscr.getch())
        stdscr.clear()
        stdscr.addstr("Key {!r} pressed".format(ch))

if __name__ == "__main__":
    wrapper(main)

keypress.py

# https://stackoverflow.com/a/21659588

# barebones approach in terminal

import termios

import sys, tty

def getch():
    fd = sys.stdin.fileno()
    old_settings = termios.tcgetattr(fd)
    try:
        tty.setraw(fd)
        ch = sys.stdin.read(1)
    finally:
        termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
    return ch

# you can also do `from keypress import getch`, and this part of the code won't
# run
if __name__ == "__main__":
    ch = ''
    while ch != 'q':
        ch = getch()
        print("\nEntered {!r}".format(ch))

pygame_continuous.py

# https://stackoverflow.com/a/27732925

# this approach allows you to continuously query if a key is down. this is only
# really possible with something like pygame.

# this method will tell you exactly which keys are currently pressed, probably
# well over several hundred times per second, as opposed to telling you when a
# key is pressed, once per press, like all the other methods

import pygame
import sys

pygame.init()

pygame.display.set_mode((100, 100))

while True:
    keys = pygame.key.get_pressed()
    print("Keys pressed: {}".format([chr(i) for i, p in enumerate(keys) if p]), end=" ")
    if keys[pygame.K_LEFT]:
        print("going left")
    elif keys[pygame.K_RIGHT]:
        print("going right")
    elif keys[pygame.K_UP]:
        print("going up")
    elif keys[pygame.K_DOWN]:
        print("going down")
    elif keys[pygame.K_q]:
        sys.exit()
    else:
        print("nothing to see here")
    pygame.event.pump()

pygame_keypress.py

# https://stackoverflow.com/a/27732925

# this approach will work in both idle and terminal, *if you have pygame
# installed*
# if not installed, you may try some variation of

#     pip install pygame
#or   pip install --user pygame

# (commands to be executed at command line)

# These do require pip, and an internet connection

import pygame
import sys
pygame.init()

pygame.display.set_mode((100, 100))

while True:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()
        if event.type == pygame.KEYDOWN:
            # the chr thing is similar to curses
            print("Key {!r} pressed".format(chr(event.key)))