如何從終端偵測腳本中的鍵盤輸入？
同步/阻塞按鍵擷取：
簡單輸入或 raw_input、阻塞函數，一旦使用者按下換行符，就會傳回使用者輸入的文字。
<code class="python">typedString = raw_input()</code>
登入後複製
一個簡單的阻塞函數，等待使用者按下單一鍵，然後返回該鍵
<code class="python">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)
def getKey():
inkey = _Getch()
import sys
for i in xrange(sys.maxint):
k=inkey()
if k<>'':break
return k</code>登入後複製
非同步按鍵擷取：
每當使用者在指令當提示符號中鍵入按鍵時，即使在解釋器（鍵盤記錄器）中鍵入內容，也會使用按下的按鍵調用回調
回調尚未實現。
使用者按下Enter 鍵後使用鍵入的文字呼叫的回呼（不太即時的鍵盤記錄器）
回呼尚未實現
程式執行階段（例如，在for 迴圈或while 迴圈中）按下按鍵時呼叫的回呼
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 = ""
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("Capture is already going")
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>登入後複製
輪詢：
輪詢：
<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] & ~termios.ICANON & ~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>登入後複製
使用者只是希望能夠在按下某個鍵時執行某些操作，而不必等待該鍵（因此這應該是非阻塞的） 。因此，他們調用 poll() 函數，該函數要么返回一個鍵，要么返回 None。這可以是有損的（如果它們在輪詢之間花費太長時間，它們可能會錯過一個鍵）或非有損的（輪詢器將存儲所有按下的鍵的歷史記錄，因此當poll( ) 當函數請求它們時，它們將始終被返回按按下的順序）。 Windows 和 OS X（也許還有 Linux）：
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