有没有办法从用户输入中读取一个字符？例如，他们在终端上按一个键并返回（有点像getch()）。我知道 Windows 中有一个功能，但我想要跨平台的东西。
Evan Fosmark
问问题
329783 次
25 回答
219
这是 ActiveState Recipes 站点的链接，该站点说明了如何在 Windows、Linux 和 OSX 中读取单个字符：
在 Windows 和 Unix 上从标准输入读取类似 getch() 的无缓冲字符
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()
于 2009-02-04T07:11:04.313 回答
92
sys.stdin.read(1)
基本上会从 STDIN 读取 1 个字节。
如果您必须使用不等待的方法，\n您可以按照上一个答案中的建议使用此代码：
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()
于 2009-02-04T07:30:51.713 回答
77
在两个答案中逐字引用的 ActiveState配方是过度设计的。可以归结为：
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()
于 2014-02-09T13:27:42.640 回答
68
同样值得尝试的是readchar库，它部分基于其他答案中提到的 ActiveState 配方。
安装：
pip install readchar
用法：
import readchar
print("Reading a char:")
print(repr(readchar.readchar()))
print("Reading a key:")
print(repr(readchar.readkey()))
使用 Python 2.7 在 Windows 和 Linux 上测试。
在 Windows 上，仅支持映射到字母或 ASCII 控制代码的键（Backspace、Enter、Esc、Tab、Ctrl+字母）。在 GNU/Linux 上（可能取决于确切的终端？）您还可以得到Insert, Delete, Pg Up, Pg Dn, Home,End和键...但是，将这些特殊键与.F nEsc
警告：就像这里的大多数（全部？）答案一样，信号键（如Ctrl+ C、Ctrl+D和Ctrl+ Z）被捕获并返回（分别为'\x03'和'\x04'）'\x1a'；您的程序可能很难中止。
于 2014-08-16T18:47:41.187 回答
21
另一种方法：
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
从这篇博文。
于 2011-08-31T15:30:40.340 回答
13
（当前）排名靠前的答案（使用 ActiveState 代码）过于复杂。当仅仅一个函数就足够时，我看不到使用类的理由。下面是两个实现相同的功能但代码更易读的实现。
这两种实现：
- 在 Python 2 或 Python 3 中工作得很好
- 在 Windows、OSX 和 Linux 上工作
- 只读取一个字节（即，他们不等待换行符）
- 不依赖任何外部库
- 是自包含的（函数定义之外没有代码）
版本 1：可读且简单
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
版本 2：避免重复导入和异常处理：
[编辑]我错过了 ActiveState 代码的一个优势。如果您计划多次读取字符，则该代码避免了在类 Unix 系统上重复 Windows 导入和 ImportError 异常处理的（可忽略的）成本。虽然您可能应该更关心代码的可读性而不是微不足道的优化，但这里有一个替代方法（它类似于 Louis 的答案，但 getChar() 是自包含的），其功能与 ActiveState 代码相同并且更具可读性：
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()
执行上述任一 getChar() 版本的示例代码：
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))
于 2016-05-02T02:49:47.370 回答
12
如果按下+或+ ，此代码基于此处，将正确引发 KeyboardInterrupt 和 EOFError 。CtrlCCtrlD
应该在 Windows 和 Linux 上工作。OS X 版本可从原始来源获得。
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()
于 2014-01-01T05:13:33.227 回答
8
尝试使用这个：http ://home.wlu.edu/~levys/software/kbhit.py 它是非阻塞的（这意味着你可以有一个while循环并检测按键而不停止它）和跨平台。
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 != []
一个使用这个的例子：
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()
或者你可以使用PyPi 的 getch 模块。但这会阻塞while循环
于 2015-07-21T21:42:36.843 回答
8
这里的答案提供了丰富的信息，但是我还想要一种方法来异步获取按键并在单独的事件中触发按键，所有这些都以线程安全、跨平台的方式进行。PyGame 对我来说也太臃肿了。所以我做了以下（在 Python 2.7 中，但我怀疑它很容易移植），我想我会在这里分享，以防它对其他人有用。我将它存储在一个名为 keyPress.py 的文件中。
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()
这个想法是您可以简单地调用keyPress.getKey()，它将从键盘读取一个键，然后返回它。
如果你想要更多的东西，我做了一个KeyCapture对象。您可以通过类似keys = keyPress.KeyCapture().
然后你可以做三件事：
addEvent(functionName)接受任何接受一个参数的函数。然后每次按下一个键时，都会调用这个函数，并在输入时使用该键的字符串。这些在单独的线程中运行，因此您可以阻止所有您想要的，它不会弄乱 KeyCapturer 的功能，也不会延迟其他事件。
get()以与以前相同的阻塞方式返回一个键。现在在这里需要它，因为现在正在通过KeyCapture对象捕获键，因此keyPress.getKey()会与该行为发生冲突，并且它们都会丢失一些键，因为一次只能捕获一个键。另外，假设用户按'a'，然后按'b'，你打电话get()，用户按'c'。该get()调用将立即返回'a'，然后如果再次调用它，它将返回'b'，然后是'c'。如果再次调用它，它将阻塞，直到按下另一个键。这样可以确保您不会错过任何键，如果需要，可以采用阻塞方式。keyPress.getKey()所以这种方式和以前有点不同
如果你想要getKey()back 的行为，get(lossy=True)就像get()，除了它只返回调用后get()按下的键。所以在上面的例子中，get()会阻塞直到用户按下'c'，然后如果你再次调用它，它将阻塞直到按下另一个键。
getAsync()有点不同。它是为进行大量处理而设计的，然后偶尔会返回并检查按下了哪些键。因此getAsync()返回自上次调用以来按下的所有键的列表，getAsync()从最旧的键按下到最近按下的键。它也不会阻塞，这意味着如果自上次调用以来没有按下任何键，则将返回getAsync()一个空 值。[]
要真正开始捕获键，您需要使用上面创建keys.startCapture()的keys对象进行调用。startCapture是非阻塞的，只需启动一个只记录按键的线程，另一个线程来处理这些按键。有两个线程来确保记录按键的线程不会错过任何键。
如果您想停止捕获密钥，您可以调用keys.stopCapture()它会停止捕获密钥。但是，由于捕获键是一种阻塞操作，因此捕获键的线程可能会在调用之后再捕获一个键stopCapture()。
为了防止这种情况，您可以将一个可选参数传递给startCapture(functionName, args)一个函数，该函数只执行检查键是否等于“c”然后退出之类的操作。重要的是这个函数之前做的很少，例如，这里的睡眠会导致我们错过按键。
但是，如果stopCapture()在此函数中调用，键捕获将立即停止，不再尝试捕获，并且所有get()调用将立即返回，如果尚未按下任何键，则返回 None。
此外，由于get()并getAsync()存储所有先前按下的键（直到您检索它们），您可以调用clearGetList()并clearAsyncList()忘记先前按下的键。
注意get(),getAsync()和 事件是独立的，所以如果按下一个键：
- 一个正在等待的呼叫
get()，有损打开，将返回该密钥。其他等待呼叫（如果有）将继续等待。 - 该键将存储在获取键的队列中，因此
get()有损关闭将返回尚未返回的最旧的键get()。 - 所有事件都将使用该键作为输入触发
- 该键将存储在
getAsync()键列表中，该列表将被返回并在下一次调用时设置为空列表getAsync()
如果这一切都太多了，这里有一个示例用例：
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"
从我所做的简单测试来看，它对我来说效果很好，但如果我错过了一些东西，我也会很乐意接受其他人的反馈。
我也在这里发布了这个。
于 2015-07-31T15:17:50.213 回答
5
这可能是上下文管理器的一个用例。抛开 Windows 操作系统的津贴，这是我的建议：
#!/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 <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 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()
于 2014-09-28T20:07:19.743 回答
5
如果我正在做一些复杂的事情，我会使用 curses 来读取密钥。但是很多时候我只想要一个简单的 Python 3 脚本，它使用标准库并且可以读取箭头键，所以我这样做：
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
于 2018-09-23T00:07:19.833 回答
4
这是非阻塞的，读取一个键并将其存储在 keypress.key 中。
import Tkinter as tk
class Keypress:
def __init__(self):
self.root = tk.Tk()
self.root.geometry('300x200')
self.root.bind('<KeyPress>', self.onKeyPress)
def onKeyPress(self, event):
self.key = event.char
def __eq__(self, other):
return self.key == other
def __str__(self):
return self.key
在你的程序中
keypress = Keypress()
while something:
do something
if keypress == 'c':
break
elif keypress == 'i':
print('info')
else:
print("i dont understand %s" % keypress)
于 2014-06-22T20:40:36.597 回答
4
ActiveState 的配方似乎包含一个防止Ctrl-C中断的“posix”系统的小错误（我使用的是 Mac）。如果我将以下代码放入我的脚本中：
while(True):
print(getch())
我将永远无法用 终止脚本Ctrl-C，我必须杀死我的终端才能逃脱。
我相信下面这行是原因，也太残酷了：
tty.setraw(sys.stdin.fileno())
除此之外，包装tty并不是真正需要的，termios足以处理它。
以下是适用于我的改进代码（Ctrl-C将中断），具有在您键入时回显字符的额外getche功能：
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)
参考：
于 2018-01-07T10:09:21.063 回答
3
用 pygame 试试这个：
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, "."
于 2015-02-21T00:36:21.317 回答
3
其他答案之一中的评论提到了 cbreak 模式，这对于 Unix 实现很重要，因为您通常不希望 ^C ( KeyboardError) 被 getchar 使用（就像当您将终端设置为原始模式时一样，通过大多数其他答案）。
另一个重要的细节是，如果你想读取一个字符而不是一个字节，你应该从输入流中读取 4 个字节，因为这是 UTF-8 中单个字符包含的最大字节数（Python 3+ ）。对于多字节字符（如键盘箭头），只读取一个字节会产生意想不到的结果。
这是我为 Unix 更改的实现：
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 restores 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)
于 2017-07-23T15:17:19.160 回答
3
您可以使用click。它经过充分测试，可在 Linux、Mac 和 Windows 上运行。
import click
print('Continue? [yn] ')
c = click.getchar() # Gets a single character
if c == 'y':
print('We will go on')
elif c == 'n':
print('Abort!')
else:
print('Invalid input :(')
于 2021-08-17T16:07:30.800 回答
2
python中的curses包可用于从终端输入“原始”模式，只需几条语句。Curses的主要用途是接管屏幕进行输出，这可能不是你想要的。此代码片段使用print()了可用的语句，但您必须了解 curses 如何更改附加到输出的行尾。
#!/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!')
于 2014-12-29T17:38:01.803 回答
1
我相信这是最优雅的解决方案之一。
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
然后在代码中使用它：
if getch() == chr(ESC_ASCII_VALUE):
print("ESC!")
于 2017-11-29T09:14:25.800 回答
1
最简单的跨平台解决方案是sshkeyboard。安装pip install sshkeyboard，
然后编写脚本，例如：
from sshkeyboard import listen_keyboard
def press(key):
print(f"'{key}' pressed")
def release(key):
print(f"'{key}' released")
listen_keyboard(
on_press=press,
on_release=release,
)
它会打印：
'a' pressed
'a' released
When A key is pressed. ESC key ends the listening by default.
It requires less coding than for example curses, tkinter and getch.
于 2021-10-28T07:44:56.660 回答
0
我对 python3 的解决方案，不依赖于任何 pip 包。
# 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())
于 2016-01-28T01:24:52.527 回答
0
接受的答案对我来说表现不佳（我会按住一个键，什么都不会发生，然后我会按另一个键，它会起作用）。
在了解了curses模块之后，这似乎是正确的方法。现在可以通过windows-cursors（通过 pip 获得）在 Windows 上使用它，因此您可以以与平台无关的方式进行编程。这是一个受YouTube 上这个不错的教程启发的示例：
import curses
def getkey(stdscr):
curses.curs_set(0)
while True:
key = stdscr.getch()
if key != -1:
break
return key
if __name__ == "__main__":
print(curses.wrapper(getkey))
.py使用扩展名保存它，或curses.wrapper(getkey)以交互模式运行。
于 2019-07-22T00:17:24.290 回答
0
在这里回答：python中的raw_input而不按回车
使用此代码-
from tkinter import Tk, Frame
def __set_key(e, root):
"""
e - event with attribute 'char', the released key
"""
global key_pressed
if e.char:
key_pressed = e.char
root.destroy()
def get_key(msg="Press any key ...", time_to_sleep=3):
"""
msg - set to empty string if you don't want to print anything
time_to_sleep - default 3 seconds
"""
global key_pressed
if msg:
print(msg)
key_pressed = None
root = Tk()
root.overrideredirect(True)
frame = Frame(root, width=0, height=0)
frame.bind("<KeyRelease>", lambda f: __set_key(f, root))
frame.pack()
root.focus_set()
frame.focus_set()
frame.focus_force() # doesn't work in a while loop without it
root.after(time_to_sleep * 1000, func=root.destroy)
root.mainloop()
root = None # just in case
return key_pressed
def __main():
c = None
while not c:
c = get_key("Choose your weapon ... ", 2)
print(c)
if __name__ == "__main__":
__main()
参考：https ://github.com/unfor19/mg-tools/blob/master/mgtools/get_key_pressed.py
于 2019-09-01T07:38:25.770 回答
0
如果您只想注册一个按键，即使用户按下它不止一次或按住按键的时间更长。为避免获得多个按下的输入，请使用 while 循环并传递它。
import keyboard
while(True):
if(keyboard.is_pressed('w')):
s+=1
while(keyboard.is_pressed('w')):
pass
if(keyboard.is_pressed('s')):
s-=1
while(keyboard.is_pressed('s')):
pass
print(s)
于 2019-10-07T11:39:57.957 回答
-2
内置 raw_input 应该会有所帮助。
for i in range(3):
print ("So much work to do!")
k = raw_input("Press any key to continue...")
print ("Ok, back to work.")
于 2015-12-15T20:51:36.410 回答
-2
如果您只想按住屏幕以便在终端上看到结果，只需编写
input()
在代码的末尾，它将保持屏幕
于 2020-01-01T17:42:02.083 回答