What s the simplest way of detecting keyboard input in a script from the terminal

Question

I have a simple python script  that has some functions that run in a loop  I m taking sensor readings    while True      print  Doing a function    If the keyboard is pressed I d like to print  key pressed    What s the simplest way of doing this in Python  I ve searched high and low  I ve found out how to do it with pygame  but I d rather do it without  If I do have to use pygame is it possible to not have a separate window for the application    import pygame  time from pygame locals import    pygame init   screen   pygame display set mode  640  480   pygame display set caption  Pygame Keyboard Test   pygame mouse set visible 0    while True      print  doing a function       for event in pygame event get          if  event type    KEYUP  or  event type    KEYDOWN            print  key pressed           time sleep 0 1

User · Answer

The Python Documentation provides this snippet to get single characters from the keyboard:

import termios, fcntl, sys, os
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)
            if c:
                print("Got character", repr(c))
        except IOError: pass
finally:
    termios.tcsetattr(fd, termios.TCSAFLUSH, oldterm)
    fcntl.fcntl(fd, fcntl.F_SETFL, oldflags)

You can also use the PyHook module to get your job done.

User · Answer

Well  since the date of this question post  a Python library addressed this topic  pynput library  from Moses Palmer  is GREAT to catch keyboard and mouse events in a very simple way    GitHub repository is here  https   github com moses-palmer pynput PyPi project is there  enter link description here and installation of lib is easy   pip install pynput     mind the missing  i  in pynput - I missed it too     -

User · Answer

Edit   I ve thought about this problem a lot  and there are a few different behaviors one could want  I ve been implementing most of them for Unix and Windows  and will post them here once they are done   Synchronous Blocking key capture    A simple input or raw input  a blocking function which returns text typed by a user once they press a newline  A simple blocking function that waits for the user to press a single key  then returns that key   Asynchronous key capture    A callback that is called with the pressed key whenever the user types a key into the command prompt  even when typing things into an interpreter  a keylogger  A callback that is called with the typed text after the user presses enter  a less realtime keylogger  A callback that is called with the keys pressed when a program is running  say  in a for loop or while loop    Polling    The user simply wants to be able to do something when a key is pressed  without having to wait for that key  so this should be non-blocking   Thus they call a poll   function and that either returns a key  or returns None  This can either be lossy  if they take too long to between poll they can miss a key  or non-lossy  the poller will store the history of all keys pressed  so when the poll   function requests them they will always be returned in the order pressed   The same as 1  except that poll only returns something once the user presses a newline    Robots   These are something that can be called to programmatically fire keyboard events  This can be used alongside key captures to echo them back out to the user  Implementations  Synchronous Blocking key capture   A simple input or raw input  a blocking function which returns text typed by a user once they press a newline   typedString   raw input     A simple blocking function that waits for the user to press a single key  then returns that key  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  amp  0x000000FF    def getKey        inkey    Getch       import sys     for i in xrange sys maxint           k inkey           if k lt  gt    break      return k   Asynchronous key capture   A callback that is called with the pressed key whenever the user types a key into the command prompt  even when typing things into an interpreter  a keylogger   A callback that is called with the typed text after the user presses enter  a less realtime keylogger   Windows   This uses the windows Robot given below  naming the script keyPress py    Some if this is from http   nullege com codes show src e i einstein-HEAD Python25Einstein Lib subprocess py 380 win32api GetStdHandle   and   http   nullege com codes show src v i VistA-HEAD Python Pexpect winpexpect py 901 win32console GetStdHandle PeekConsoleInput  from ctypes import   import time import threading  from win32api import STD INPUT HANDLE  STD OUTPUT HANDLE  from win32console import GetStdHandle  KEY EVENT  ENABLE WINDOW INPUT  ENABLE MOUSE INPUT  ENABLE ECHO INPUT  ENABLE LINE INPUT  ENABLE PROCESSED INPUT  import keyPress   class CaptureLines        def   init   self           self stopLock   threading Lock            self isCapturingInputLines   False          self inputLinesHookCallback   CFUNCTYPE c int  self inputLinesHook          self pyosInputHookPointer   c void p in dll pythonapi   PyOS InputHook           self originalPyOsInputHookPointerValue   self pyosInputHookPointer value          self readHandle   GetStdHandle STD INPUT HANDLE          self readHandle SetConsoleMode ENABLE LINE INPUT ENABLE ECHO INPUT ENABLE PROCESSED INPUT       def inputLinesHook self            self readHandle SetConsoleMode ENABLE LINE INPUT ENABLE ECHO INPUT ENABLE PROCESSED INPUT          inputChars   self readHandle ReadConsole 10000000          self readHandle SetConsoleMode ENABLE LINE INPUT ENABLE PROCESSED INPUT           if inputChars      r n               keyPress KeyPress   n               return 0          inputChars   inputChars  -2           inputChars      n           for c in inputChars              keyPress KeyPress c           self inputCallback inputChars           return 0       def startCapture self  inputCallback           self stopLock acquire            try              if self isCapturingInputLines                  raise Exception  Already capturing keystrokes                self isCapturingInputLines   True             self inputCallback   inputCallback              self pyosInputHookPointer value   cast self inputLinesHookCallback  c void p  value         except Exception as e              self stopLock release               raise          self stopLock release        def stopCapture self           self stopLock acquire            try              if not self isCapturingInputLines                  raise Exception  Keystrokes already aren t being captured                self readHandle SetConsoleMode ENABLE LINE INPUT ENABLE ECHO INPUT ENABLE PROCESSED INPUT               self isCapturingInputLines   False             self pyosInputHookPointer value   self originalPyOsInputHookPointerValue          except Exception as e              self stopLock release               raise          self stopLock release     A callback that is called with the keys pressed when a program is running  say  in a for loop or while loop   Windows   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     Polling   The user simply wants to be able to do something when a key is pressed  without having to wait for that key  so this should be non-blocking   Thus they call a poll   function and that either returns a key  or returns None  This can either be lossy  if they take too long to between poll they can miss a key  or non-lossy  the poller will store the history of all keys pressed  so when the poll   function requests them they will always be returned in the order pressed    Windows and OS X  and maybe Linux    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               if len eventsPeek     0                  return None              if not len eventsPeek     self curEventLength                  for curEvent in eventsPeek self curEventLength                        if curEvent EventType    KEY EVENT                          if ord curEvent Char     0 or not curEvent KeyDown                              pass                         else                              curChar   str curEvent Char                              self capturedChars append curChar                  self curEventLength   len eventsPeek               if not len self capturedChars     0                  return self capturedChars pop 0              else                  return None         else              dr dw de   select select  sys stdin           0              if not dr                        return sys stdin read 1              return None   Simple use case   with KeyPoller   as keyPoller      while True          c   keyPoller poll           if not c is None              if c     c                   break             print c   The same as above  except that poll only returns something once the user presses a newline   Robots   These are something that can be called to programmatically fire keyboard events  This can be used alongside key captures to echo them back out to the user  Windows     Modified from http   stackoverflow com a 13615802 2924421  import ctypes from ctypes import wintypes import time  user32   ctypes WinDLL  user32   use last error True   INPUT MOUSE      0 INPUT KEYBOARD   1 INPUT HARDWARE   2  KEYEVENTF EXTENDEDKEY   0x0001 KEYEVENTF KEYUP         0x0002 KEYEVENTF UNICODE       0x0004 KEYEVENTF SCANCODE      0x0008  MAPVK VK TO VSC   0    C struct definitions wintypes ULONG PTR   wintypes WPARAM  SendInput   ctypes windll user32 SendInput  PUL   ctypes POINTER ctypes c ulong   class KEYBDINPUT ctypes Structure        fields       wVk           wintypes WORD                     wScan         wintypes WORD                     dwFlags       wintypes DWORD                     time          wintypes DWORD                     dwExtraInfo   wintypes ULONG PTR    class MOUSEINPUT ctypes Structure        fields       dx            wintypes LONG                     dy            wintypes LONG                     mouseData     wintypes DWORD                     dwFlags       wintypes DWORD                     time          wintypes DWORD                     dwExtraInfo   wintypes ULONG PTR    class HARDWAREINPUT ctypes Structure        fields       uMsg      wintypes DWORD                     wParamL   wintypes WORD                     wParamH   wintypes WORD    class INPUT ctypes Structure       class  INPUT ctypes Union            fields       ki   KEYBDINPUT                         mi   MOUSEINPUT                         hi   HARDWAREINPUT        anonymous       input         fields       type     wintypes DWORD                      input    INPUT    LPINPUT   ctypes POINTER INPUT   def  check count result  func  args       if result    0          raise ctypes WinError ctypes get last error        return args  user32 SendInput errcheck    check count user32 SendInput argtypes    wintypes UINT    nInputs                              LPINPUT          pInputs                              ctypes c int     cbSize  def KeyDown unicodeKey       key  unikey  uniflag   GetKeyCode unicodeKey      x   INPUT  type INPUT KEYBOARD  ki  KEYBDINPUT  key  unikey  uniflag  0       user32 SendInput 1  ctypes byref x   ctypes sizeof x    def KeyUp unicodeKey       key  unikey  uniflag   GetKeyCode unicodeKey      extra   ctypes c ulong 0      x   INPUT  type INPUT KEYBOARD  ki  KEYBDINPUT  key  unikey  uniflag   KEYEVENTF KEYUP  0       user32 SendInput 1  ctypes byref x   ctypes sizeof x    def KeyPress unicodeKey       time sleep 0 0001      KeyDown unicodeKey      time sleep 0 0001      KeyUp unicodeKey      time sleep 0 0001    def GetKeyCode unicodeKey       k   unicodeKey     curKeyCode   0     if k     up   curKeyCode   0x26     elif k     down   curKeyCode   0x28     elif k     left   curKeyCode   0x25     elif k     right   curKeyCode   0x27     elif k     home   curKeyCode   0x24     elif k     end   curKeyCode   0x23     elif k     insert   curKeyCode   0x2D     elif k     pgup   curKeyCode   0x21     elif k     pgdn   curKeyCode   0x22     elif k     delete   curKeyCode   0x2E     elif k      n   curKeyCode   0x0D      if curKeyCode    0          return 0  int unicodeKey encode  hex    16   KEYEVENTF UNICODE     else          return curKeyCode  0  0   OS X      usr bin env python  import time from Quartz CoreGraphics import CGEventCreateKeyboardEvent from Quartz CoreGraphics import CGEventPost    Python releases things automatically  using CFRelease will result in a scary error  from Quartz CoreGraphics import CFRelease  from Quartz CoreGraphics import kCGHIDEventTap    From http   stackoverflow com questions 281133 controlling-the-mouse-from-python-in-os-x   and from https   developer apple com library mac documentation Carbon Reference QuartzEventServicesRef index html   apple ref c func CGEventCreateKeyboardEvent   def KeyDown k       keyCode  shiftKey   toKeyCode k       time sleep 0 0001       if shiftKey          CGEventPost kCGHIDEventTap  CGEventCreateKeyboardEvent None  0x38  True           time sleep 0 0001       CGEventPost kCGHIDEventTap  CGEventCreateKeyboardEvent None  keyCode  True       time sleep 0 0001       if shiftKey          CGEventPost kCGHIDEventTap  CGEventCreateKeyboardEvent None  0x38  False           time sleep 0 0001   def KeyUp k       keyCode  shiftKey   toKeyCode k       time sleep 0 0001       CGEventPost kCGHIDEventTap  CGEventCreateKeyboardEvent None  keyCode  False       time sleep 0 0001   def KeyPress k       keyCode  shiftKey   toKeyCode k       time sleep 0 0001       if shiftKey          CGEventPost kCGHIDEventTap  CGEventCreateKeyboardEvent None  0x38  True           time sleep 0 0001       CGEventPost kCGHIDEventTap  CGEventCreateKeyboardEvent None  keyCode  True       time sleep 0 0001       CGEventPost kCGHIDEventTap  CGEventCreateKeyboardEvent None  keyCode  False       time sleep 0 0001       if shiftKey          CGEventPost kCGHIDEventTap  CGEventCreateKeyboardEvent None  0x38  False           time sleep 0 0001       From http   stackoverflow com questions 3202629 where-can-i-find-a-list-of-mac-virtual-key-codes  def toKeyCode c       shiftKey   False       Letter     if c isalpha            if not c islower                shiftKey   True             c   c lower        if c in shiftChars          shiftKey   True         c   shiftChars c      if c in keyCodeMap          keyCode   keyCodeMap c      else          keyCode   ord c      return keyCode  shiftKey  shiftChars                             1             2             3             4             5             6         amp     7             8             9             0             -                                                                                               lt               gt                          keyCodeMap          a                    0x00       s                    0x01       d                    0x02       f                    0x03       h                    0x04       g                    0x05       z                    0x06       x                    0x07       c                    0x08       v                    0x09       b                    0x0B       q                    0x0C       w                    0x0D       e                    0x0E       r                    0x0F       y                    0x10       t                    0x11       1                    0x12       2                    0x13       3                    0x14       4                    0x15       6                    0x16       5                    0x17                            0x18       9                    0x19       7                    0x1A       -                    0x1B       8                    0x1C       0                    0x1D                            0x1E       o                    0x1F       u                    0x20                            0x21       i                    0x22       p                    0x23       l                    0x25       j                    0x26                            0x27       k                    0x28                            0x29                            0x2A                            0x2B                            0x2C       n                    0x2D       m                    0x2E                            0x2F                            0x32       k                    0x41       k                    0x43       k                    0x45       kclear               0x47       k                    0x4B       k n                  0x4C       k-                   0x4E       k                    0x51       k0                   0x52       k1                   0x53       k2                   0x54       k3                   0x55       k4                   0x56       k5                   0x57       k6                   0x58       k7                   0x59       k8                   0x5B       k9                   0x5C         keycodes for keys that are independent of keyboard layout       n                   0x24        t                   0x30                            0x31       del                  0x33       delete               0x33       esc                  0x35       escape               0x35       cmd                  0x37       command              0x37       shift                0x38       caps lock            0x39       option               0x3A       ctrl                 0x3B       control              0x3B       right shift          0x3C       rshift               0x3C       right option         0x3D       roption              0x3D       right control        0x3E       rcontrol             0x3E       fun                  0x3F       function             0x3F       f17                  0x40       volume up            0x48       volume down          0x49       mute                 0x4A       f18                  0x4F       f19                  0x50       f20                  0x5A       f5                   0x60       f6                   0x61       f7                   0x62       f3                   0x63       f8                   0x64       f9                   0x65       f11                  0x67       f13                  0x69       f16                  0x6A       f14                  0x6B       f10                  0x6D       f12                  0x6F       f15                  0x71       help                 0x72       home                 0x73       pgup                 0x74       page up              0x74       forward delete       0x75       f4                   0x76       end                  0x77       f2                   0x78       page down            0x79       pgdn                 0x79       f1                   0x7A       left                 0x7B       right                0x7C       down                 0x7D       up                   0x7E

User · Answer

These functions  based on the above  seem to work well for getting characters from the keyboard  blocking and non-blocking    import termios  fcntl  sys  os  def get char keyboard      fd   sys stdin fileno      oldterm   termios tcgetattr fd    newattr   termios tcgetattr fd    newattr 3    newattr 3   amp   termios ICANON  amp   termios ECHO   termios tcsetattr fd  termios TCSANOW  newattr     c   None   try      c   sys stdin read 1    except IOError  pass    termios tcsetattr fd  termios TCSAFLUSH  oldterm     return c  def get char keyboard nonblock      fd   sys stdin fileno      oldterm   termios tcgetattr fd    newattr   termios tcgetattr fd    newattr 3    newattr 3   amp   termios ICANON  amp   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     c   None    try      c   sys stdin read 1    except IOError  pass    termios tcsetattr fd  termios TCSAFLUSH  oldterm    fcntl fcntl fd  fcntl F SETFL  oldflags     return c

User · Answer

One of the simplest way I found is to use pynput module can be found here with nice examples as well  from pynput import keyboard  def on press key       try          print  alphanumeric key  0  pressed  format              key char       except AttributeError          print  special key  0  pressed  format              key    def on release key       print   0  released  format          key       if key    keyboard Key esc            Stop listener         return False    Collect events until released with keyboard Listener          on press on press          on release on release  as listener      listener join     above is the example worked out for me and to install  go  for python 2        pip install pynput   for python 3        pip3 install pynput

User · Answer

This needs run as root   Warning  this is a system-wide keylogger       usr bin python3  import signal import keyboard import time import os   if not os geteuid      0    print  This script needs to be run as root      exit    def exitNice signum  frame     global running    running   False  def keyEvent e     global running   if e event type     up       print  Key up      str e name     if e event type     down       print  Key down      str e name     if e name     q       exitNice             print  Quitting    running   True signal signal signal SIGINT  exitNice  keyboard hook keyEvent   print  Press  q  to quit   fps   1 24 while running    time sleep fps

User · Answer

import turtle  wn   turtle Screen   turtle   turtle Turtle    def printLetter        print  a    turtle listen   turtle onkey printLetter   a

User · Answer

I wrote a more easy-to-use implementation for  enrico bacis s answer  It supports both Linux python2 7 and python3 5  and Windows python2 7   It may support Mac OS  but I didn t test it  If you tried it on Mac  please tell me the result       Author  Yu Lou Date  2017-02-23  Based on the answer by  enrico bacis in http   stackoverflow com a 13207724 4398908 and  Phylliida in http   stackoverflow com a 31736883 4398908        Import modules try      try          import termios  fcntl  sys  os  curses   Import modules for Linux     except ImportError          import msvcrt   Import module for Windows except ImportError      raise Exception  This platform is not supported     class KeyGetterLinux              Implemented kbhit    getch   and getchar   in Linux       Tested on Ubuntu 16 10 Linux 4 8 0   Python 2 7 12 and Python 3 5 2             def   init   self           self buffer        A buffer to store the character read by kbhit         self started   False   Whether initialization is complete      def kbhit self  echo   False                       Return whether a key is hitten                      if not self buffer              if echo                  self buffer   self getchar block   False              else                  self buffer   self getch block   False           return bool self buffer       def getch self  block   True                       Return a single character without echo          If block is False and no input is currently available  return an empty string without waiting                      try              curses initscr               curses noecho               return self getchar block          finally              curses endwin        def getchar self  block   True                       Return a single character and echo          If block is False and no input is currently available  return an empty string without waiting                      self  start           try              return self  getchar block          finally              self  stop        def  getchar self  block   True                       Return a single character and echo          If block is False and no input is currently available  return a empty string without waiting          Should be called between self  start   and self  end                       assert self started     getchar   is called before  start                Change the terminal setting         if block              fcntl fcntl self fd  fcntl F SETFL  self old flags  amp   os O NONBLOCK          else              fcntl fcntl self fd  fcntl F SETFL  self old flags   os O NONBLOCK           if self buffer    Use the character in buffer first             result   self buffer             self buffer              else              try                  result   sys stdin read 1              except IOError    In python 2 7  using read   when no input is available will result in IOError                  return             return result      def  start self                       Initialize the terminal                      assert not self started    start   is called twice           self fd   sys stdin fileno            self old attr   termios tcgetattr self fd           new attr   termios tcgetattr self fd          new attr 3    new attr 3   amp   termios ICANON         termios tcsetattr self fd  termios TCSANOW  new attr           self old flags   fcntl fcntl self fd  fcntl F GETFL           self started   True      def  stop self                       Restore the terminal                      assert self started    start   is not called           termios tcsetattr self fd  termios TCSAFLUSH  self old attr          fcntl fcntl self fd  fcntl F SETFL  self old flags           self started   False        Magic functions for context manager     def   enter   self           self  start           self getchar   self  getchar   No need for self  start   now         return self      def   exit   self  type  value  traceback           self  stop           return False  class KeyGetterWindows              kbhit   and getchar   in Windows       Tested on Windows 7 64 bit  Python 2 7 1             def kbhit self  echo           return msvcrt kbhit        def getchar self  block   True           if not block and not msvcrt kbhit                return            return msvcrt getchar        def getch self  block   True           if not block and not msvcrt kbhit                return            return msvcrt getch         getchar   getchar        Magic functions for context manager     def   enter   self           return self      def   exit   self  type  value  traceback           return False  try      import termios     KeyGetter   KeyGetterLinux   Use KeyGetterLinux if termios exists except ImportError      KeyGetter   KeyGetterWindows   Use KeyGetterWindows otherwise   This is an example assume that you saved the codes above in  key getter py     from key getter import KeyGetter import time  def test1      Test with block False     print  test1        k   KeyGetter       try          while True              if k kbhit                    print  Got   repr k getch False                    print  Got   repr k getch False                else                  print  Nothing                time sleep 0 5      except KeyboardInterrupt          pass     print input  Enter something      def test2      Test context manager with block True     print  test2        with KeyGetter   as k          try              while True                  if k kbhit                        print  Got   repr k getchar True                        print  Got   repr k getchar True                    else                      print  Nothing                    time sleep 0 5          except KeyboardInterrupt              pass     print input  Enter something      test1   test2

User · Answer

This worked for me on macOS Sierra and Python 2 7 10 and 3 6 3  import sys tty os termios def getkey        old settings   termios tcgetattr sys stdin      tty setcbreak sys stdin fileno        try          while True              b   os read sys stdin fileno    3  decode               if len b     3                  k   ord b 2               else                  k   ord b              key mapping                     127   backspace                   10   return                   32   space                   9   tab                   27   esc                   65   up                   66   down                   67   right                   68   left                            return key mapping get k  chr k       finally          termios tcsetattr sys stdin  termios TCSADRAIN  old settings  try      while True          k   getkey           if k     esc               quit           else              print k  except  KeyboardInterrupt  SystemExit       os system  stty sane       print  stopping

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Inspired from code found above  credits   the simple blocking  aka not CPU consuming  macOS version I was looking for   import termios import sys import fcntl import os  def getKeyCode blocking   True       fd   sys stdin fileno       oldterm   termios tcgetattr fd      newattr   termios tcgetattr fd      newattr 3    newattr 3   amp   termios ICANON  amp   termios ECHO     termios tcsetattr fd  termios TCSANOW  newattr      if not blocking          oldflags   fcntl fcntl fd  fcntl F GETFL          fcntl fcntl fd  fcntl F SETFL  oldflags   os O NONBLOCK      try          return ord sys stdin read 1       except IOError          return 0     finally          termios tcsetattr fd  termios TCSAFLUSH  oldterm          if not blocking              fcntl fcntl fd  fcntl F SETFL  oldflags   def getKeyStroke        code    getKeyCode       if code    27          code2   getKeyCode blocking   False          if code2    0              return  esc          elif code2    91              code3   getKeyCode blocking   False              if code3    65                  return  up              elif code3    66                  return  down              elif code3    68                  return  left              elif code3    67                  return  right              else                  return  esc       elif code    127          return  backspace      elif code    9          return  tab      elif code    10          return  return      elif code    195 or code    194                  code2   getKeyCode blocking   False          return chr code  chr code2    utf-8 char     else          return chr code    while True      print getKeyStroke     2017-11-09  EDITED  Not tested with Python 3

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You can use methods from http   docs python org 2 library msvcrt html if you are on Windows   import msvcrt      while True      print  Doing a function      if msvcrt kbhit            print  Key pressed   s    msvcrt getch

[python] What's the simplest way of detecting keyboard input in a script from the terminal?

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