如何检测从终端运行的 Python 脚本中的键盘输入？

如何从终端检测脚本中的键盘输入？

同步/阻塞按键捕获：

简单输入或 raw_input、阻塞函数，一旦用户按下换行符，就会返回用户输入的文本。

<code class="python">typedString = raw_input()</code>

一个简单的阻塞函数，等待用户按下单个键，然后返回该键

<code class="python">class _Getch:
 &quot;&quot;&quot;Gets a single character from standard input.  Does not echo to the
screen. From http://code.activestate.com/recipes/134892/&quot;&quot;&quot;
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:
&quot;&quot;&quot;
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.
&quot;&quot;&quot;
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 &amp; 0x000000FF)


def getKey():
  inkey = _Getch()
  import sys
  for i in xrange(sys.maxint):
    k=inkey()
    if k<>'':break

  return k</code>

异步按键捕获：

每当用户在命令提示符中键入按键时，即使在解释器（键盘记录器）中键入内容，也会使用按下的按键调用回调

回调尚未实现。

用户按下 Enter 键后使用键入的文本调用的回调（不太实时的键盘记录器）

回调尚未实现

程序运行时（例如，在 for 循环或 while 循环中）按下按键时调用的回调

Windows:

<code class="python">import threading
from win32api import STD_INPUT_HANDLE
from win32console import GetStdHandle, KEY_EVENT, ENABLE_ECHO_INPUT, ENABLE_LINE_INPUT, ENABLE_PROCESSED_INPUT


class KeyAsyncReader():
  def __init__(self):
    self.stopLock = threading.Lock()
    self.stopped = True
    self.capturedChars = &quot;&quot;

    self.readHandle = GetStdHandle(STD_INPUT_HANDLE)
    self.readHandle.SetConsoleMode(ENABLE_LINE_INPUT|ENABLE_ECHO_INPUT|ENABLE_PROCESSED_INPUT)



  def startReading(self, readCallback):
    self.stopLock.acquire()

    try:
      if not self.stopped:
        raise Exception(&quot;Capture is already going&quot;)

      self.stopped = False
      self.readCallback = readCallback

      backgroundCaptureThread = threading.Thread(target=self.backgroundThreadReading)
      backgroundCaptureThread.daemon = True
      backgroundCaptureThread.start()
    except:
      self.stopLock.release()
      raise

    self.stopLock.release()


  def backgroundThreadReading(self):
    curEventLength = 0
    curKeysLength = 0
    while True:
      eventsPeek = self.readHandle.PeekConsoleInput(10000)

      self.stopLock.acquire()
      if self.stopped:
        self.stopLock.release()
        return
      self.stopLock.release()


      if len(eventsPeek) == 0:
        continue

      if not len(eventsPeek) == curEventLength:
        if self.getCharsFromEvents(eventsPeek[curEventLength:]):
          self.stopLock.acquire()
          self.stopped = True
          self.stopLock.release()
          break

        curEventLength = len(eventsPeek)



  def getCharsFromEvents(self, eventsPeek):
    callbackReturnedTrue = False
    for curEvent in eventsPeek:
      if curEvent.EventType == KEY_EVENT:
              if ord(curEvent.Char) == 0 or not curEvent.KeyDown:
                pass
              else:
                curChar = str(curEvent.Char)
                if self.readCallback(curChar) == True:
                  callbackReturnedTrue = True


    return callbackReturnedTrue

  def stopReading(self):
    self.stopLock.acquire()
    self.stopped = True
    self.stopLock.release()</code>

轮询：

用户只是希望能够在按下某个键时执行某些操作，而不必等待该键（因此这应该是非阻塞的） 。因此，他们调用 poll() 函数，该函数要么返回一个键，要么返回 None。这可以是有损的（如果它们在轮询之间花费太长时间，它们可能会错过一个键）或非有损的（轮询器将存储所有按下的键的历史记录，因此当 poll() 函数请求它们时，它们将始终被返回按按下的顺序）。

Windows 和 OS X（也许还有 Linux）：

<code class="python">global isWindows

isWindows = False
try:
  from win32api import STD_INPUT_HANDLE
  from win32console import GetStdHandle, KEY_EVENT, ENABLE_ECHO_INPUT, ENABLE_LINE_INPUT, ENABLE_PROCESSED_INPUT
  isWindows = True
except ImportError as e:
  import sys
  import select
  import termios


class KeyPoller():
  def __enter__(self):
    global isWindows
    if isWindows:
      self.readHandle = GetStdHandle(STD_INPUT_HANDLE)
      self.readHandle.SetConsoleMode(ENABLE_LINE_INPUT|ENABLE_ECHO_INPUT|ENABLE_PROCESSED_INPUT)
      
      self.curEventLength = 0
      self.curKeysLength = 0
      
      self.capturedChars = []
    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] &amp; ~termios.ICANON &amp; ~termios.ECHO)
      termios.tcsetattr(self.fd, termios.TCSAFLUSH, self.new_term)
      
    return self
  
  def __exit__(self, type, value, traceback):
    if isWindows:
      pass
    else:
      termios.tcsetattr(self.fd, termios.TCSAFLUSH, self.old_term)
  
  def poll(self):
    if isWindows:
      if not len(self.capturedChars) == 0:
        return self.capturedChars.pop(0)

      eventsPeek = self.readHandle.PeekConsoleInput(10000)
</code>

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