Python lee un solo carácter del usuario

¿Hay una manera de leer un solo carácter de la entrada del usuario? Por ejemplo, presionan una tecla en el terminal y se devuelve (algo así como getch() ). Sé que hay una función en Windows para eso, pero me gustaría algo que sea multiplataforma.

Aquí hay un enlace a un sitio que dice cómo puede leer un solo carácter en Windows, Linux y OSX: http://code.activestate.com/recipes/134892/

 class _Getch: """Gets a single character from standard input. Does not echo to the screen.""" def __init__(self): try: self.impl = _GetchWindows() except ImportError: self.impl = _GetchUnix() def __call__(self): return self.impl() class _GetchUnix: def __init__(self): import tty, sys def __call__(self): import sys, tty, termios fd = sys.stdin.fileno() old_settings = termios.tcgetattr(fd) try: tty.setraw(sys.stdin.fileno()) ch = sys.stdin.read(1) finally: termios.tcsetattr(fd, termios.TCSADRAIN, old_settings) return ch class _GetchWindows: def __init__(self): import msvcrt def __call__(self): import msvcrt return msvcrt.getch() getch = _Getch() 
 sys.stdin.read(1) 

Básicamente leerá 1 byte de STDIN.

Si debe usar el método que no espera al \n , puede usar este código como se sugiere en la respuesta anterior:

 class _Getch: """Gets a single character from standard input. Does not echo to the screen.""" def __init__(self): try: self.impl = _GetchWindows() except ImportError: self.impl = _GetchUnix() def __call__(self): return self.impl() class _GetchUnix: def __init__(self): import tty, sys def __call__(self): import sys, tty, termios fd = sys.stdin.fileno() old_settings = termios.tcgetattr(fd) try: tty.setraw(sys.stdin.fileno()) ch = sys.stdin.read(1) finally: termios.tcsetattr(fd, termios.TCSADRAIN, old_settings) return ch class _GetchWindows: def __init__(self): import msvcrt def __call__(self): import msvcrt return msvcrt.getch() getch = _Getch() 

( tomado de http://code.activestate.com/recipes/134892/ )

La receta de ActiveState citada textualmente en dos respuestas está sobre diseñada. Se puede reducir a esto:

 def _find_getch(): try: import termios except ImportError: # Non-POSIX. Return msvcrt's (Windows') getch. import msvcrt return msvcrt.getch # POSIX system. Create and return a getch that manipulates the tty. 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 return _getch getch = _find_getch() 

También vale la pena probar la biblioteca readchar , que en parte se basa en la receta ActiveState mencionada en otras respuestas.

Instalación:

 pip install readchar 

Uso:

 import readchar print("Reading a char:") print(repr(readchar.readchar())) print("Reading a key:") print(repr(readchar.readkey())) 

Probado en Windows y Linux con Python 2.7.

En Windows, solo se admiten las teclas que se asignan a letras o códigos de control ASCII ( Retroceso , Intro , Esc , Tab , Ctrl + letra ). En GNU / Linux (dependiendo del terminal exacto, ¿quizás?) También obtiene las teclas Insertar , Eliminar , Pg Up , Pg Dn , Inicio , Fin y F n … pero luego, hay problemas que separan estas teclas especiales de una Esc .

Advertencia: como con la mayoría de las respuestas (¿todas?) Aquí, las teclas de señal como Ctrl + C , Ctrl + D y Ctrl + Z se capturan y devuelven (como '\x03' , '\x04' y '\x1a' respectivamente); Su progtwig puede ser difícil de abortar.

Un método alternativo:

 import os import sys import termios import fcntl def getch(): fd = sys.stdin.fileno() oldterm = termios.tcgetattr(fd) newattr = termios.tcgetattr(fd) newattr[3] = newattr[3] & ~termios.ICANON & ~termios.ECHO termios.tcsetattr(fd, termios.TCSANOW, newattr) oldflags = fcntl.fcntl(fd, fcntl.F_GETFL) fcntl.fcntl(fd, fcntl.F_SETFL, oldflags | os.O_NONBLOCK) try: while 1: try: c = sys.stdin.read(1) break except IOError: pass finally: termios.tcsetattr(fd, termios.TCSAFLUSH, oldterm) fcntl.fcntl(fd, fcntl.F_SETFL, oldflags) return c 

De esta entrada de blog .

Creo que se vuelve extremadamente torpe en este punto, y la depuración en las diferentes plataformas es un gran lío.

Estarás mejor usando algo como pyglet, pygame, cocos2d, si estás haciendo algo más elaborado y necesitarás imágenes, o maldiciones si vas a trabajar con el terminal.

Curses es estándar: http://docs.python.org/library/curses.html

Este código, basado aquí , levantará correctamente KeyboardInterrupt y EOFError si se presionan Ctrl + C o Ctrl + D.

Debería funcionar en Windows y Linux. Una versión de OS X está disponible en la fuente original.

 class _Getch: """Gets a single character from standard input. Does not echo to the screen.""" def __init__(self): try: self.impl = _GetchWindows() except ImportError: self.impl = _GetchUnix() def __call__(self): char = self.impl() if char == '\x03': raise KeyboardInterrupt elif char == '\x04': raise EOFError return char class _GetchUnix: def __init__(self): import tty import sys def __call__(self): import sys import tty import termios fd = sys.stdin.fileno() old_settings = termios.tcgetattr(fd) try: tty.setraw(sys.stdin.fileno()) ch = sys.stdin.read(1) finally: termios.tcsetattr(fd, termios.TCSADRAIN, old_settings) return ch class _GetchWindows: def __init__(self): import msvcrt def __call__(self): import msvcrt return msvcrt.getch() getch = _Getch() 

La respuesta mejor clasificada (actualmente) (con el código ActiveState) es demasiado complicada. No veo una razón para usar clases cuando una mera función debería ser suficiente. A continuación se muestran dos implementaciones que logran lo mismo pero con un código más legible.

Ambas implementaciones:

  1. funciona bien en Python 2 o Python 3
  2. Trabajar en Windows, OSX y Linux.
  3. lea solo un byte (es decir, no esperan una nueva línea)
  4. No dependa de ninguna biblioteca externa.
  5. son autónomos (sin código fuera de la definición de la función)

Versión 1: legible y simple.

 def getChar(): try: # for Windows-based systems import msvcrt # If successful, we are on Windows return msvcrt.getch() except ImportError: # for POSIX-based systems (with termios & tty support) import tty, sys, termios # raises ImportError if unsupported fd = sys.stdin.fileno() oldSettings = termios.tcgetattr(fd) try: tty.setcbreak(fd) answer = sys.stdin.read(1) finally: termios.tcsetattr(fd, termios.TCSADRAIN, oldSettings) return answer 

Versión 2: evitar las importaciones repetidas y el manejo de excepciones:

[EDITAR] Me perdí una ventaja del código ActiveState. Si planea leer caracteres varias veces, ese código evita el costo (despreciable) de repetir la importación de Windows y el manejo de excepciones ImportError en sistemas similares a Unix. Si bien probablemente debería estar más preocupado por la legibilidad del código que esa optimización insignificante, aquí hay una alternativa (es similar a la respuesta de Louis, pero getChar () es independiente) que funciona igual que el código ActiveState y es más legible:

 def getChar(): # figure out which function to use once, and store it in _func if "_func" not in getChar.__dict__: try: # for Windows-based systems import msvcrt # If successful, we are on Windows getChar._func=msvcrt.getch except ImportError: # for POSIX-based systems (with termios & tty support) import tty, sys, termios # raises ImportError if unsupported def _ttyRead(): fd = sys.stdin.fileno() oldSettings = termios.tcgetattr(fd) try: tty.setcbreak(fd) answer = sys.stdin.read(1) finally: termios.tcsetattr(fd, termios.TCSADRAIN, oldSettings) return answer getChar._func=_ttyRead return getChar._func() 

Código de ejemplo que ejerce cualquiera de las versiones de getChar () anteriores:

 from __future__ import print_function # put at top of file if using Python 2 # Example of a prompt for one character of input promptStr = "Please give me a character:" responseStr = "Thank you for giving me a '{}'." print(promptStr, end="\n> ") answer = getChar() print("\n") print(responseStr.format(answer)) 

Este podría ser un caso de uso para un administrador de contexto. Dejando a un lado las concesiones para el sistema operativo Windows, he aquí mi sugerencia:

 #!/usr/bin/env python3 # file: 'readchar.py' """ Implementation of a way to get a single character of input without waiting for the user to hit . (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 test(): while True: with ReadChar() as rc: char = rc if ord(char) <= 32: print("You entered character with ordinal {}."\ .format(ord(char))) else: print("You entered character '{}'."\ .format(char)) if char in "^C^D": sys.exit() if __name__ == "__main__": test() 

Las respuestas aquí fueron informativas, sin embargo, también quería una forma de presionar las teclas de forma asíncrona y disparar las teclas en eventos separados, todo en una forma multiplataforma segura para subprocesos. PyGame también estaba demasiado hinchado para mí. Así que hice lo siguiente (en Python 2.7, pero sospecho que es fácilmente portátil), que pensé que compartiría aquí en caso de que fuera útil para alguien más. Guardé esto en un archivo llamado keyPress.py.

 class _Getch: """Gets a single character from standard input. Does not echo to the screen. From http://code.activestate.com/recipes/134892/""" def __init__(self): try: self.impl = _GetchWindows() except ImportError: try: self.impl = _GetchMacCarbon() except(AttributeError, ImportError): self.impl = _GetchUnix() def __call__(self): return self.impl() class _GetchUnix: def __init__(self): import tty, sys, termios # import termios now or else you'll get the Unix version on the Mac def __call__(self): import sys, tty, termios fd = sys.stdin.fileno() old_settings = termios.tcgetattr(fd) try: tty.setraw(sys.stdin.fileno()) ch = sys.stdin.read(1) finally: termios.tcsetattr(fd, termios.TCSADRAIN, old_settings) return ch class _GetchWindows: def __init__(self): import msvcrt def __call__(self): import msvcrt return msvcrt.getch() class _GetchMacCarbon: """ A function which returns the current ASCII key that is down; if no ASCII key is down, the null string is returned. The page http://www.mactech.com/macintosh-c/chap02-1.html was very helpful in figuring out how to do this. """ def __init__(self): import Carbon Carbon.Evt #see if it has this (in Unix, it doesn't) def __call__(self): import Carbon if Carbon.Evt.EventAvail(0x0008)[0]==0: # 0x0008 is the keyDownMask return '' else: # # The event contains the following info: # (what,msg,when,where,mod)=Carbon.Evt.GetNextEvent(0x0008)[1] # # The message (msg) contains the ASCII char which is # extracted with the 0x000000FF charCodeMask; this # number is converted to an ASCII character with chr() and # returned # (what,msg,when,where,mod)=Carbon.Evt.GetNextEvent(0x0008)[1] return chr(msg & 0x000000FF) import threading # From https://stackoverflow.com/a/2022629/2924421 class Event(list): def __call__(self, *args, **kwargs): for f in self: f(*args, **kwargs) def __repr__(self): return "Event(%s)" % list.__repr__(self) def getKey(): inkey = _Getch() import sys for i in xrange(sys.maxint): k=inkey() if k<>'':break return k class KeyCallbackFunction(): callbackParam = None actualFunction = None def __init__(self, actualFunction, callbackParam): self.actualFunction = actualFunction self.callbackParam = callbackParam def doCallback(self, inputKey): if not self.actualFunction is None: if self.callbackParam is None: callbackFunctionThread = threading.Thread(target=self.actualFunction, args=(inputKey,)) else: callbackFunctionThread = threading.Thread(target=self.actualFunction, args=(inputKey,self.callbackParam)) callbackFunctionThread.daemon = True callbackFunctionThread.start() class KeyCapture(): gotKeyLock = threading.Lock() gotKeys = [] gotKeyEvent = threading.Event() keyBlockingSetKeyLock = threading.Lock() addingEventsLock = threading.Lock() keyReceiveEvents = Event() keysGotLock = threading.Lock() keysGot = [] keyBlockingKeyLockLossy = threading.Lock() keyBlockingKeyLossy = None keyBlockingEventLossy = threading.Event() keysBlockingGotLock = threading.Lock() keysBlockingGot = [] keyBlockingGotEvent = threading.Event() wantToStopLock = threading.Lock() wantToStop = False stoppedLock = threading.Lock() stopped = True isRunningEvent = False getKeyThread = None keyFunction = None keyArgs = None # Begin capturing keys. A seperate thread is launched that # captures key presses, and then these can be received via get, # getAsync, and adding an event via addEvent. Note that this # will prevent the system to accept keys as normal (say, if # you are in a python shell) because it overrides that key # capturing behavior. # If you start capture when it's already been started, a # InterruptedError("Keys are still being captured") # will be thrown # Note that get(), getAsync() and events are independent, so if a key is pressed: # # 1: Any calls to get() that are waiting, with lossy on, will return # that key # 2: It will be stored in the queue of get keys, so that get() with lossy # off will return the oldest key pressed not returned by get() yet. # 3: All events will be fired with that key as their input # 4: It will be stored in the list of getAsync() keys, where that list # will be returned and set to empty list on the next call to getAsync(). # get() call with it, aand add it to the getAsync() list. def startCapture(self, keyFunction=None, args=None): # Make sure we aren't already capturing keys self.stoppedLock.acquire() if not self.stopped: self.stoppedLock.release() raise InterruptedError("Keys are still being captured") return self.stopped = False self.stoppedLock.release() # If we have captured before, we need to allow the get() calls to actually # wait for key presses now by clearing the event if self.keyBlockingEventLossy.is_set(): self.keyBlockingEventLossy.clear() # Have one function that we call every time a key is captured, intended for stopping capture # as desired self.keyFunction = keyFunction self.keyArgs = args # Begin capturing keys (in a seperate thread) self.getKeyThread = threading.Thread(target=self._threadProcessKeyPresses) self.getKeyThread.daemon = True self.getKeyThread.start() # Process key captures (in a seperate thread) self.getKeyThread = threading.Thread(target=self._threadStoreKeyPresses) self.getKeyThread.daemon = True self.getKeyThread.start() def capturing(self): self.stoppedLock.acquire() isCapturing = not self.stopped self.stoppedLock.release() return isCapturing # Stops the thread that is capturing keys on the first opporunity # has to do so. It usually can't stop immediately because getting a key # is a blocking process, so this will probably stop capturing after the # next key is pressed. # # However, Sometimes if you call stopCapture it will stop before starting capturing the # next key, due to multithreading race conditions. So if you want to stop capturing # reliably, call stopCapture in a function added via addEvent. Then you are # guaranteed that capturing will stop immediately after the rest of the callback # functions are called (before starting to capture the next key). def stopCapture(self): self.wantToStopLock.acquire() self.wantToStop = True self.wantToStopLock.release() # Takes in a function that will be called every time a key is pressed (with that # key passed in as the first paramater in that function) def addEvent(self, keyPressEventFunction, args=None): self.addingEventsLock.acquire() callbackHolder = KeyCallbackFunction(keyPressEventFunction, args) self.keyReceiveEvents.append(callbackHolder.doCallback) self.addingEventsLock.release() def clearEvents(self): self.addingEventsLock.acquire() self.keyReceiveEvents = Event() self.addingEventsLock.release() # Gets a key captured by this KeyCapture, blocking until a key is pressed. # There is an optional lossy paramater: # If True all keys before this call are ignored, and the next pressed key # will be returned. # If False this will return the oldest key captured that hasn't # been returned by get yet. False is the default. def get(self, lossy=False): if lossy: # Wait for the next key to be pressed self.keyBlockingEventLossy.wait() self.keyBlockingKeyLockLossy.acquire() keyReceived = self.keyBlockingKeyLossy self.keyBlockingKeyLockLossy.release() return keyReceived else: while True: # Wait until a key is pressed self.keyBlockingGotEvent.wait() # Get the key pressed readKey = None self.keysBlockingGotLock.acquire() # Get a key if it exists if len(self.keysBlockingGot) != 0: readKey = self.keysBlockingGot.pop(0) # If we got the last one, tell us to wait if len(self.keysBlockingGot) == 0: self.keyBlockingGotEvent.clear() self.keysBlockingGotLock.release() # Process the key (if it actually exists) if not readKey is None: return readKey # Exit if we are stopping self.wantToStopLock.acquire() if self.wantToStop: self.wantToStopLock.release() return None self.wantToStopLock.release() def clearGetList(self): self.keysBlockingGotLock.acquire() self.keysBlockingGot = [] self.keysBlockingGotLock.release() # Gets a list of all keys pressed since the last call to getAsync, in order # from first pressed, second pressed, .., most recent pressed def getAsync(self): self.keysGotLock.acquire(); keysPressedList = list(self.keysGot) self.keysGot = [] self.keysGotLock.release() return keysPressedList def clearAsyncList(self): self.keysGotLock.acquire(); self.keysGot = [] self.keysGotLock.release(); def _processKey(self, readKey): # Append to list for GetKeyAsync self.keysGotLock.acquire() self.keysGot.append(readKey) self.keysGotLock.release() # Call lossy blocking key events self.keyBlockingKeyLockLossy.acquire() self.keyBlockingKeyLossy = readKey self.keyBlockingEventLossy.set() self.keyBlockingEventLossy.clear() self.keyBlockingKeyLockLossy.release() # Call non-lossy blocking key events self.keysBlockingGotLock.acquire() self.keysBlockingGot.append(readKey) if len(self.keysBlockingGot) == 1: self.keyBlockingGotEvent.set() self.keysBlockingGotLock.release() # Call events added by AddEvent self.addingEventsLock.acquire() self.keyReceiveEvents(readKey) self.addingEventsLock.release() def _threadProcessKeyPresses(self): while True: # Wait until a key is pressed self.gotKeyEvent.wait() # Get the key pressed readKey = None self.gotKeyLock.acquire() # Get a key if it exists if len(self.gotKeys) != 0: readKey = self.gotKeys.pop(0) # If we got the last one, tell us to wait if len(self.gotKeys) == 0: self.gotKeyEvent.clear() self.gotKeyLock.release() # Process the key (if it actually exists) if not readKey is None: self._processKey(readKey) # Exit if we are stopping self.wantToStopLock.acquire() if self.wantToStop: self.wantToStopLock.release() break self.wantToStopLock.release() def _threadStoreKeyPresses(self): while True: # Get a key readKey = getKey() # Run the potential shut down function if not self.keyFunction is None: self.keyFunction(readKey, self.keyArgs) # Add the key to the list of pressed keys self.gotKeyLock.acquire() self.gotKeys.append(readKey) if len(self.gotKeys) == 1: self.gotKeyEvent.set() self.gotKeyLock.release() # Exit if we are stopping self.wantToStopLock.acquire() if self.wantToStop: self.wantToStopLock.release() self.gotKeyEvent.set() break self.wantToStopLock.release() # If we have reached here we stopped capturing # All we need to do to clean up is ensure that # all the calls to .get() now return None. # To ensure no calls are stuck never returning, # we will leave the event set so any tasks waiting # for it immediately exit. This will be unset upon # starting key capturing again. self.stoppedLock.acquire() # We also need to set this to True so we can start up # capturing again. self.stopped = True self.stopped = True self.keyBlockingKeyLockLossy.acquire() self.keyBlockingKeyLossy = None self.keyBlockingEventLossy.set() self.keyBlockingKeyLockLossy.release() self.keysBlockingGotLock.acquire() self.keyBlockingGotEvent.set() self.keysBlockingGotLock.release() self.stoppedLock.release() 

La idea es que simplemente puede llamar a keyPress.getKey() , que leerá una tecla del teclado y luego la devolverá.

Si quieres algo más que eso, hice un objeto KeyCapture . Puedes crear uno a través de algo como keys = keyPress.KeyCapture() .

Luego hay tres cosas que puedes hacer:

addEvent(functionName) toma cualquier función que tome un parámetro. Luego, cada vez que se presione una tecla, se llamará a esta función con la cadena de esa tecla como entrada. Estos se ejecutan en un hilo separado, por lo que puede bloquear todo lo que quiera en ellos y no arruinará la funcionalidad del KeyCapturer ni retrasará los otros eventos.

get() devuelve una clave de la misma forma de locking que antes. Ahora se necesita aquí porque las claves se capturan a través del objeto KeyCapture ahora, por lo que keyPress.getKey() entraría en conflicto con ese comportamiento y ambas perderían algunas claves ya que solo se puede capturar una clave a la vez. Además, diga que el usuario presiona ‘a’, luego ‘b’, usted llama get() , el usuario presiona ‘c’. Esa llamada get() devolverá inmediatamente ‘a’, luego, si la llama nuevamente, devolverá ‘b’, luego ‘c’. Si lo vuelves a llamar, se bloqueará hasta que se presione otra tecla. Esto asegura que no se pierda ninguna clave, de forma bloqueada si se desea. Así que de esta manera es un poco diferente a keyPress.getKey() de antes

Si desea que el comportamiento de getKey() vuelva, get(lossy=True) es como get() , excepto que solo devuelve las teclas presionadas después de la llamada para get() . Entonces, en el ejemplo anterior, get() bloquearía hasta que el usuario presione ‘c’, y luego, si lo llama nuevamente, bloqueará hasta que se presione otra tecla.

getAsync() es un poco diferente. Está diseñado para algo que procesa mucho, y luego, ocasionalmente, vuelve y comprueba qué teclas se presionaron. Por getAsync() tanto, getAsync() devuelve una lista de todas las teclas presionadas desde la última llamada a getAsync() , en orden desde la tecla más antigua presionada hasta la tecla más reciente presionada. Tampoco se bloquea, lo que significa que si no se han presionado teclas desde la última llamada a getAsync() , se getAsync() un [] vacío.

Para comenzar a capturar claves, debe llamar a keys.startCapture() con el objeto de keys que se hizo arriba. startCapture no es de locking, y simplemente inicia un hilo que simplemente registra las pulsaciones de teclas, y otro hilo para procesar esas pulsaciones de teclas. Hay dos hilos para garantizar que el hilo que registra las pulsaciones de teclas no se pierda ninguna tecla.

Si desea detener la captura de claves, puede llamar a keys.stopCapture() y dejará de capturar las claves. Sin embargo, dado que la captura de una clave es una operación de locking, las claves de captura de subprocesos pueden capturar una clave más después de llamar a stopCapture() .

Para evitar esto, puede pasar uno o startCapture(functionName, args) parámetros opcionales a startCapture(functionName, args) de una función que solo hace algo como verificar si una tecla es igual a ‘c’ y luego sale. Es importante que esta función haga muy poco antes, por ejemplo, una suspensión aquí nos hará perder las teclas.

Sin embargo, si se llama a stopCapture() en esta función, las capturas de las teclas se detendrán inmediatamente, sin intentar capturar más, y todas las llamadas get() se devolverán de inmediato, con Ninguna si no se han presionado las teclas aún.

Además, dado que get() y getAsync() almacenan todas las teclas anteriores presionadas (hasta que las recuperas), puedes llamar a clearGetList() y clearAsyncList() para olvidar las teclas presionadas previamente.

Tenga en cuenta que get() , getAsync() y los eventos son independientes, por lo que si se presiona una tecla: 1. Una llamada a get() que está en espera, con la pérdida activada, devolverá esa tecla. Las otras llamadas en espera (si las hay) continuarán esperando. 2. Esa clave se almacenará en la cola de las claves de obtención, de modo que get() con pérdida desactivada devolverá la clave más antigua que no haya sido devuelta por get() . 3. Todos los eventos se activarán con esa clave como entrada. 4. Esa clave se almacenará en la lista de getAsync() de getAsync() , donde se devolverá esa lista y se establecerá en una lista vacía en la próxima llamada a getAsync()

Si todo esto es demasiado, aquí hay un ejemplo de un caso de uso:

 import keyPress import time import threading def KeyPressed(k, printLock): printLock.acquire() print "Event: " + k printLock.release() time.sleep(4) printLock.acquire() print "Event after delay: " + k printLock.release() def GetKeyBlocking(keys, printLock): while keys.capturing(): keyReceived = keys.get() time.sleep(1) printLock.acquire() if not keyReceived is None: print "Block " + keyReceived else: print "Block None" printLock.release() def GetKeyBlockingLossy(keys, printLock): while keys.capturing(): keyReceived = keys.get(lossy=True) time.sleep(1) printLock.acquire() if not keyReceived is None: print "Lossy: " + keyReceived else: print "Lossy: None" printLock.release() def CheckToClose(k, (keys, printLock)): printLock.acquire() print "Close: " + k printLock.release() if k == "c": keys.stopCapture() printLock = threading.Lock() print "Press a key:" print "You pressed: " + keyPress.getKey() print "" keys = keyPress.KeyCapture() keys.addEvent(KeyPressed, printLock) print "Starting capture" keys.startCapture(CheckToClose, (keys, printLock)) getKeyBlockingThread = threading.Thread(target=GetKeyBlocking, args=(keys, printLock)) getKeyBlockingThread.daemon = True getKeyBlockingThread.start() getKeyBlockingThreadLossy = threading.Thread(target=GetKeyBlockingLossy, args=(keys, printLock)) getKeyBlockingThreadLossy.daemon = True getKeyBlockingThreadLossy.start() while keys.capturing(): keysPressed = keys.getAsync() printLock.acquire() if keysPressed != []: print "Async: " + str(keysPressed) printLock.release() time.sleep(1) print "done capturing" 

Me está funcionando bien con la prueba simple que hice, pero con gusto tomaré la retroalimentación de los demás también si hay algo que omití.

He publicado esto aquí también.

Esto es NO BLOQUEO, lee una clave y la almacena en keypress.key.

 import Tkinter as tk class Keypress: def __init__(self): self.root = tk.Tk() self.root.geometry('300x200') self.root.bind('', self.onKeyPress) def onKeyPress(self, event): self.key = event.char def __eq__(self, other): return self.key == other def __str__(self): return self.key 

en tu progtwig

 keypress = Keypress() while something: do something if keypress == 'c': break elif keypress == 'i': print('info') else: print("i dont understand %s" % keypress) 

Intente usar esto: http://home.wlu.edu/~levys/software/kbhit.py Es no bloqueante (eso significa que puede tener un bucle while y detectar una pulsación de tecla sin detenerlo) y multiplataforma.

 import os # Windows if os.name == 'nt': import msvcrt # Posix (Linux, OS X) else: import sys import termios import atexit from select import select class KBHit: def __init__(self): '''Creates a KBHit object that you can call to do various keyboard things.''' if os.name == 'nt': pass else: # Save the terminal settings self.fd = sys.stdin.fileno() self.new_term = termios.tcgetattr(self.fd) self.old_term = termios.tcgetattr(self.fd) # New terminal setting unbuffered self.new_term[3] = (self.new_term[3] & ~termios.ICANON & ~termios.ECHO) termios.tcsetattr(self.fd, termios.TCSAFLUSH, self.new_term) # Support normal-terminal reset at exit atexit.register(self.set_normal_term) def set_normal_term(self): ''' Resets to normal terminal. On Windows this is a no-op. ''' if os.name == 'nt': pass else: termios.tcsetattr(self.fd, termios.TCSAFLUSH, self.old_term) def getch(self): ''' Returns a keyboard character after kbhit() has been called. Should not be called in the same program as getarrow(). ''' s = '' if os.name == 'nt': return msvcrt.getch().decode('utf-8') else: return sys.stdin.read(1) def getarrow(self): ''' Returns an arrow-key code after kbhit() has been called. Codes are 0 : up 1 : right 2 : down 3 : left Should not be called in the same program as getch(). ''' if os.name == 'nt': msvcrt.getch() # skip 0xE0 c = msvcrt.getch() vals = [72, 77, 80, 75] else: c = sys.stdin.read(3)[2] vals = [65, 67, 66, 68] return vals.index(ord(c.decode('utf-8'))) def kbhit(self): ''' Returns True if keyboard character was hit, False otherwise. ''' if os.name == 'nt': return msvcrt.kbhit() else: dr,dw,de = select([sys.stdin], [], [], 0) return dr != [] 

An example to use this:

 import kbhit kb = kbhit.KBHit() while(True): print("Key not pressed") #Do something if kb.kbhit(): #If a key is pressed: k_in = kb.getch() #Detect what key was pressed print("You pressed ", k_in, "!") #Do something kb.set_normal_term() 

Or you could use the getch module from PyPi . But this would block the while loop

A comment in one of the other answers mentioned cbreak mode, which is important for Unix implementations because you generally don’t want ^C ( KeyboardError ) to be consumed by getchar (as it will when you set the terminal to raw mode, as done by most other answers).

Another important detail is that if you’re looking to read one character and not one byte , you should read 4 bytes from the input stream, as that’s the maximum number of bytes a single character will consist of in UTF-8 (Python 3+). Reading only a single byte will produce unexpected results for multi-byte characters such as keypad arrows.

Here’s my changed implementation for Unix:

 import contextlib import os import sys import termios import tty _MAX_CHARACTER_BYTE_LENGTH = 4 @contextlib.contextmanager def _tty_reset(file_descriptor): """ A context manager that saves the tty flags of a file descriptor upon entering and restres them upon exiting. """ old_settings = termios.tcgetattr(file_descriptor) try: yield finally: termios.tcsetattr(file_descriptor, termios.TCSADRAIN, old_settings) def get_character(file=sys.stdin): """ Read a single character from the given input stream (defaults to sys.stdin). """ file_descriptor = file.fileno() with _tty_reset(file_descriptor): tty.setcbreak(file_descriptor) return os.read(file_descriptor, _MAX_CHARACTER_BYTE_LENGTH) 

Try this with pygame:

 import pygame pygame.init() // eliminate error, pygame.error: video system not initialized keys = pygame.key.get_pressed() if keys[pygame.K_SPACE]: d = "space key" print "You pressed the", d, "." 

The curses package in python can be used to enter “raw” mode for character input from the terminal with just a few statements. Curses’ main use is to take over the screen for output, which may not be what you want. This code snippet uses print() statements instead, which are usable, but you must be aware of how curses changes line endings attached to output.

 #!/usr/bin/python3 # Demo of single char terminal input in raw mode with the curses package. import sys, curses def run_one_char(dummy): 'Run until a carriage return is entered' char = ' ' print('Welcome to curses', flush=True) while ord(char) != 13: char = one_char() def one_char(): 'Read one character from the keyboard' print('\r? ', flush= True, end = '') ## A blocking single char read in raw mode. char = sys.stdin.read(1) print('You entered %s\r' % char) return char ## Must init curses before calling any functions curses.initscr() ## To make sure the terminal returns to its initial settings, ## and to set raw mode and guarantee cleanup on exit. curses.wrapper(run_one_char) print('Curses be gone!') 

The ActiveState’s recipe seems to contain a little bug for “posix” systems that prevents Ctrl-C from interrupting (I’m using Mac). If I put the following code in my script:

 while(True): print(getch()) 

I will never be able to terminate the script with Ctrl-C , and I have to kill my terminal to escape.

I believe the following line is the cause, and it’s also too brutal:

 tty.setraw(sys.stdin.fileno()) 

Asides from that, package tty is not really needed, termios is enough to handle it.

Below is the improved code that works for me ( Ctrl-C will interrupt), with the extra getche function that echo the char as you type:

 if sys.platform == 'win32': import msvcrt getch = msvcrt.getch getche = msvcrt.getche else: import sys import termios def __gen_ch_getter(echo): def __fun(): fd = sys.stdin.fileno() oldattr = termios.tcgetattr(fd) newattr = oldattr[:] try: if echo: # disable ctrl character printing, otherwise, backspace will be printed as "^?" lflag = ~(termios.ICANON | termios.ECHOCTL) else: lflag = ~(termios.ICANON | termios.ECHO) newattr[3] &= lflag termios.tcsetattr(fd, termios.TCSADRAIN, newattr) ch = sys.stdin.read(1) if echo and ord(ch) == 127: # backspace # emulate backspace erasing # https://stackoverflow.com/a/47962872/404271 sys.stdout.write('\b \b') finally: termios.tcsetattr(fd, termios.TCSADRAIN, oldattr) return ch return __fun getch = __gen_ch_getter(False) getche = __gen_ch_getter(True) 

Referencias:

The build-in raw_input should help.

 for i in range(3): print ("So much work to do!") k = raw_input("Press any key to continue...") print ("Ok, back to work.") 

My solution for python3, not depending on any pip packages.

 # precondition: import tty, sys def query_yes_no(question, default=True): """ Ask the user a yes/no question. Returns immediately upon reading one-char answer. Accepts multiple language characters for yes/no. """ if not sys.stdin.isatty(): return default if default: prompt = "[Y/n]?" other_answers = "n" else: prompt = "[y/N]?" other_answers = "yjosiá" print(question,prompt,flush= True,end=" ") oldttysettings = tty.tcgetattr(sys.stdin.fileno()) try: tty.setraw(sys.stdin.fileno()) return not sys.stdin.read(1).lower() in other_answers except: return default finally: tty.tcsetattr(sys.stdin.fileno(), tty.TCSADRAIN , oldttysettings) sys.stdout.write("\r\n") tty.tcdrain(sys.stdin.fileno()) 

I believe that this is one the most elegant solution.

 import os if os.name == 'nt': import msvcrt def getch(): return msvcrt.getch().decode() else: import sys, tty, termios fd = sys.stdin.fileno() old_settings = termios.tcgetattr(fd) def getch(): try: tty.setraw(sys.stdin.fileno()) ch = sys.stdin.read(1) finally: termios.tcsetattr(fd, termios.TCSADRAIN, old_settings) return ch 

and then use it in the code:

 if getch() == chr(ESC_ASCII_VALUE): print("ESC!") 

If I’m doing something complicated I’ll use curses to read keys. But a lot of times I just want a simple Python 3 script that uses the standard library and can read arrow keys, so I do this:

 import sys, termios, tty key_Enter = 13 key_Esc = 27 key_Up = '\033[A' key_Dn = '\033[B' key_Rt = '\033[C' key_Lt = '\033[D' fdInput = sys.stdin.fileno() termAttr = termios.tcgetattr(0) def getch(): tty.setraw(fdInput) ch = sys.stdin.buffer.raw.read(4).decode(sys.stdin.encoding) if len(ch) == 1: if ord(ch) < 32 or ord(ch) > 126: ch = ord(ch) elif ord(ch[0]) == 27: ch = '\033' + ch[1:] termios.tcsetattr(fdInput, termios.TCSADRAIN, termAttr) return ch