Question

我正在研究一个python脚本，该脚本监视Arduino 101板载加速度计的串行输入。它已根据为不同的Arduino硬件编写的脚本改编（可以在here中找到）。

检测到更改时，当检测到更改时，python脚本将运行display.exe（或在Linux上为XRandR）来旋转显示。这需要与Linux和Windows一起使用。

arduino将一个字符串写入序列为<right>，<left>，<normal>和<inverted>。这些值可以在Linux上的XRandR上正常工作，但是display.exe需要度值（0、90、180、270）。因此，当direction == normal时，应将其转换为0 ... left至90，依此类推。

在我的情况下，原始代码中使用的“翻译”不起作用（在将其调整为与我的arduino的输出匹配之后），但这是一个示例供参考：

translation = {"Y_POS":"90",
                 "X_POS":"180",
                 "X_NEG":"0",
                "Y_NEG":"270"}

我将每个输入值（例如，从Y_POS更改为left），由于此操作不起作用，目前，我正在为{{1 }}。必须有一种不太冗长的方法来实现这一目标。如何做到这一点而又不必重复不必要的事情？

direction

使用# This python3.4 script is the computer-side component of my # auto-rotating display project, which rotates a computer display # automatically when the physical monitor is rotated # Terminate this script before trying to program the Arduino. # Similarly, do not have the Arduino serial viewer open whilst this script is # running import serial import string import time from subprocess import call # for sending the command to rotate import traceback # for debugging # This function tries to initialise a serial connection on dev # If no device is connected, it will fail # If a non-Arduino device is connected there, it may connect def initSerial(dev): ser = serial.Serial(dev, 9600, timeout=1, xonxoff=False, rtscts=False, dsrdtr=False) ser.flushInput() ser.flushOutput() return ser # This function tries to initialise a serial connection # It blindly tries to connect to anything on possibleDevices # If if fails, it waits then tries again. # This function does not return until it succeeds def waitForSerialInit(): # The Arduino can appear on any of these ports on my computer # It may appear on different ports for you. # To figure out which ones to use, # 1) open the Arduino IDE # 2) Click on Tools > Serial Port # The devices listed there are what you should type here possibleDevices = ["COM6", "COM3"] # Windows # possibleDevices = ["/dev/ttyACM0","/dev/ttyACM1","/dev/ttyACM2"] # Linux while True: for dev in possibleDevices: try: ser = initSerial(dev) print("device found on " + dev) return ser except Exception: print("Failed to initialise device on " + dev) time.sleep(5) # depending on what orientation your accelerometer is relative to your monitor, # you may have to adjust these. # This is for when the Y axis points to the top of the monitor, # And the bottom of the Arduino is against the monitor back # # The second string on each of these lines are the arguments sent in the # terminal command to rotate. So if you want to try this on Mac or Windows, # this is one of the things you'll need to change # # Only some of the stuff the Arduino sends will be a command # Other stuff is just diagnostics # We only want to rotate the display when the line starts and ends with # these substrings. These must match what's in monitor.ino line_start = "Rotate Monitor <" line_end = ">" # Ok, let's go. # Start by initialising a serial connection to the Arduino ser = waitForSerialInit() while True: try: line = ser.readline().decode("utf-8") except Exception: # It's probably been unplugged # # But this also catches other types of errors, # Which is not ideal. print("error: ") traceback.print_exc() print("probably not plugged in") time.sleep(5) print("trying to init serial again") ser = waitForSerialInit() continue if line == "": continue # ignore empty lines # print line for debugging purposes print("line: " + line) # check if the line starts with the special command start if line.find(line_start) == 0: #yes this is a command direction = line.replace(line_start,"") direction = direction[0:direction.find(line_end)] print("direction: " + direction) # check the direction is valid (so not NOT_SURE) if direction == "normal": command = "C:\Rotaytor\display.exe /device 2 /rotate:0" print("running: " + command) call(command, shell=True) elif direction == "left": command = "C:\Rotaytor\display.exe /device 2 /rotate:90" print("running: " + command) call(command, shell=True) elif direction == "inverted": command = "C:\Rotaytor\display.exe /device 2 /rotate:180" print("running: " + command) call(command, shell=True) elif direction == "right": command = "C:\Rotaytor\display.exe /device 2 /rotate:270" print("running: " + command) call(command, shell=True) else: print("invalid direction: " + direction) print("ignoring")时错误输出为：

translation = {"normal":"0, ...}

Answer 1

您应该可以将每个if / elif替换为：

command = "C:\Rotaytor\display.exe /device 2 /rotate:" + translation[direction]
print("running: " + command)
call(command, shell=True)

基于字典：

translation = {"normal": 0, ...}

第96行开始将是：

if line.find(line_start) == 0:
    #yes this is a command
    direction = line.replace(line_start,"")
    direction = direction[0:direction.find(line_end)]
    print("direction: " + direction)

    translation = {"normal": 0, ...}

    # check the direction is valid (so not NOT_SURE)
    if direction in translation:
        command = "C:\Rotaytor\display.exe /device 2 /rotate:" + translation[direction]
        print("running: " + command)
        call(command, shell=True)

    else:
        print("invalid direction: " + direction)
        print("ignoring")

Python：根据字符串的原始值更改它

1 个答案: