是否有办法从用户输入中读取单个字符?例如,他们在终端上按下一个键,它就会返回(有点像getch())。我知道Windows中有这个功能,但我想要跨平台的东西。


当前回答

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())

其他回答

两个答案中逐字引用的ActiveState配方是过度设计的。它可以归结为:

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()

下面是ActiveState Recipes网站的链接,告诉你如何在Windows、Linux和OSX中读取单个字符:

getch()-类似于在Windows和Unix上从stdin读取的非缓冲字符

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()

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, "."

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

摘自这篇博文。

如果您想只注册一个键,即使用户按了多次或长时间按该键也要按。 为了避免获得多个按下的输入,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)