用python模擬Raspbian中的擊鍵

Question

當試圖弄清楚如何在按下按鈕（利用GPIO管腳）後如何讓python腳本發送左或右擊鍵時，我偶然發現了this question。

似乎所選的答案是我需要讓我去，但安裝xautomation後，試圖調整代碼到我的腳本和閱讀Popen的文檔（我甚至嘗試運行一個新的與逐字的代碼）我不斷收到以下錯誤文件：

Traceback (most recent call last): 
    File "/home/zdistaging/Documents/xte test.py", line 17, in <module> 
    keypress(shift_a_sequence) 
    File "/home/zdistaging/Documents/xte test.py", line 15, in keypress 
    p.communicate(input=sequence) 
    File "/usr/lib/python3.4/subprocess.py", line 941, in communicate 
    self.stdin.write(input) 
TypeError: 'str' does not support the buffer interface 

我在皮3 B型運行Python3，在Raspbian傑西使用Pixel（從raspberrypi.org下載）

任何想法爲什麼它出錯了？

如果它有幫助，我所要做的就是允許用戶在FEH幻燈片中向左和向右滾動......我可能完全脫離這個方法，給出了這個任務看似簡單的任務是。我不是在尋找某個人爲我徹底解決這個問題 - 我喜歡與編碼相關的挑戰 - 我只是超新的python;將我推向正確的方向將會非常有幫助。

任何幫助非常感謝！

編輯：對不起，不包括代碼！

from subprocess import Popen, PIPE 

control_f4_sequence = '''keydown Control_L 
key F4 
keyup Control_L 
''' 

shift_a_sequence = '''keydown Shift_L 
key A 
keyup Shift_L 
''' 

def keypress(sequence): 
    p = Popen(['xte'], stdin=PIPE) 
    p.communicate(input=sequence) 

keypress(shift_a_sequence) 
keypress(control_f4_sequence) 

編輯編輯：

這裏是我更新的代碼...它實際打印的左，右按鍵操作空間。

import time 
import RPi.GPIO as GPIO 
from subprocess import Popen, PIPE 
GPIO.setmode(GPIO.BCM) 
GPIO.setwarnings(False) 

leftArrow = '''key \x1B[D''' # I've tried '''key Left''' 
rightArrow = '''key \x1B[C''' # and '''key Right''' with the same results 

offButton = 26  # Black wire 
onButton = 19  # White wire 
leftButton = 13  # Red wire 
rightButton = 6  # Green wire 


def keypress(sequence): 
    if isinstance(sequence, str): 
     sequence = sequence.encode('ascii') 
    p = Popen(['xte'], stdin=PIPE) 
    p.communicate(input=sequence) 


GPIO.setup(offButton, GPIO.IN, GPIO.PUD_UP) 
GPIO.setup(onButton, GPIO.IN, GPIO.PUD_UP) 
GPIO.setup(leftButton, GPIO.IN, GPIO.PUD_UP) 
GPIO.setup(rightButton, GPIO.IN, GPIO.PUD_UP) 


while True: 
    offButton_state = GPIO.input(offButton) 
    onButton_state = GPIO.input(onButton) 
    leftButton_state = GPIO.input(leftButton) 
    rightButton_state = GPIO.input(rightButton) 

    if offButton_state == GPIO.LOW: 
     print("Off button pressed") 

    if onButton_state == GPIO.LOW: 
     print("On button pressed") 

    if leftButton_state == GPIO.LOW: 
     keypress(leftArrow) 
     print("Left button pressed") 

    if rightButton_state == GPIO.LOW: 
     keypress(rightArrow) 
     print("Right button pressed") 

    time.sleep(1) 

我已經閱讀了關於subprocess and Popen.communicate()，但無法真正判斷問題是否有事可做與或有什麼xte is expecting as an argument。思考？

Answer 1

該錯誤表明您的控制序列是字符串（即unicode），但Subprocess似乎期望字節。

在功能keypress，轉換序列爲字節就像這樣：

if isinstance(sequence, str): 
    sequence = sequence.encode('ascii') 

關於字節串很好的書面記錄，和Unicode可以在這裏找到：https://nedbatchelder.com/text/unipain.html

Answer 2

我一直在尋找同樣的例子，下面是6個按鈕我的工作例如：（它有點亂，但我調試行可能會幫助別人太）

import time 
import RPi.GPIO as GPIO 
GPIO.setmode(GPIO.BCM) 
GPIO.setwarnings(False) 
from Xlib import X 
from subprocess import Popen, PIPE 

buttons = [18,   23,   24,   25,  8,  7 ] 
opcodes = ['next', 'enter', 'alt tab', 'previous', 'spacebar', 'shift' ] 
opcodes2 = ['key Left ', 'key Up ', 'key Down ', 'key Right ', 'key Enter ', 'key Shift_L '] 

# set the gpio pins 
for button in buttons: 
    GPIO.setup(button, GPIO.IN, GPIO.PUD_UP) 

def keypress(sequence): 
    #if isinstance(sequence, str): 
    #sequence = sequence.encode('ascii') 
    p = Popen(['xte', '-x:0'], stdin=PIPE) 
    p.communicate(input=sequence) 

def main(): 
    while True: 
     button_state = [] 
     for button in buttons: 
      button_state.append(GPIO.input(button)) 

     for item in range(len(button_state)): 
      if button_state[item] == 0: 
       print (opcodes2[item]) #debugging 
      # send X key for keystroke in (for the given iteration of the loop) opcodes[button.output(index)] 
       #print (repr(str(opcodes2[item]).encode('ascii'))) 
       keypress(str(opcodes2[item]).encode('ascii')) 
     print (repr(button_state)) #for debugging 
     time.sleep(0.3) 
     del button_state 

if __name__ == '__main__': 
    main() 

注意每個命令的opcodes2內的尾隨空格（可以是任何字符）。 ascii編碼丟棄了我的最後一個字符，所以這是我有點醜陋的解決方法。