python-3.x - Unicode 字符串serialport.write ("\x23o0\x23f") 不支持

Question

我们在使用以下代码时遇到困难

#Get the heading from the IMU
#Translate the IMU from magnetic north to true north since the calcs use true north
def getcurheading():
# The escape character for # is \x23 in hex
    serialport.write("\x23o0 \x23f")
    headresponse = serialport.readline()
#   print(headresponse)
    words = headresponse.split(",")
    if len(words) > 2:
        try:
            curheading = (float(words[0])) + 180
            if curheading + Declination > 360: curheading = curheading - 360 + Declination
            else: curheading = curheading + Declination
        except:
            curheading = 999
#   print(curheading)
        return curheading

这是报告的错误:

Traceback (most recent call last):
  File "solarrobot7-core.py", line 256, in <module>
    if (getcurheading() < getsolarheading()) and (getsolarangle() > 2) and (getcurheading() != 999):
  File "solarrobot7-core.py", line 118, in getcurheading
    serialport.write("\x23o0 \x23f")
  File "/usr/local/lib/python3.2/dist-packages/serial/serialposix.py", line 518, in write
    d = to_bytes(data)
  File "/usr/local/lib/python3.2/dist-packages/serial/serialutil.py", line 58, in to_bytes
    raise TypeError('unicode strings are not supported, please encode to bytes: %r' % (seq,))
TypeError: unicode strings are not supported, please encode to bytes: '#o0 #f'

看起来我可以使用:

a_string = '\x23o0 \x23f Python'
by = a_string.encode('utf-8')
serialport.write(“\x23o0 \x23f “) a serialport.write(by)

这样对吗？由于我不是编码员，因此我不确定此修复程序是否正确。我已经尝试过了，代码会继续运行，直到它抛出另一个似乎与此步骤相关的错误。这就是为什么我们在继续之前回溯以查看这是否正确。

Answer 1

在 Python 3.X 中，字符串如 "abc"默认情况下是 Unicode 字符串。必须对字符串进行编码才能传输，或者仅以字节字符串开头 b"abc" (注意 b )。其中任何一个都可以工作:

serialport.write(b"\x23o0 \x23f")

或者:

serialport.write("\x23o0 \x23f".encode('ascii'))

请注意，指定编码是可选的，默认为 utf8 .
bytearray是字节字符串的可变形式，这里并不真正需要。它应该给你一个没有在 Python 3 上编码的错误:

>>> bytearray("abc")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: string argument without an encoding
>>> bytearray("abc",'ascii')
bytearray(b'abc')

您可以编辑字节数组:

>>> bytes = bytearray("abc",'ascii')
>>> bytes[1]=50
>>> bytes
bytearray(b'a2c')

但不是字节字符串:

>>> bytes = b'abc'
>>> bytes[1] = 50
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'bytes' object does not support item assignment