Popen.communicate() 抛出 UnicodeDecodeError

Question

我有这个代码：

def __executeCommand(self, command: str, input: str = None) -> str:
    p = sub.Popen(command, stdout=sub.PIPE, stderr=sub.PIPE, stdin=sub.PIPE, universal_newlines=True)
    p.stdin.write(input)
    output, error = p.communicate()
    if (len(errors) > 0):
        raise EnvironmentError("Could not generate the key: " + error)
    elif (p.returncode != 0):
        raise EnvironmentError("Could not generate the key. Return Value: " + p.returncode)
    return output

我在该行中收到 UnicodeDecodeError output, error = p.communicate()：

Traceback (most recent call last):
  File "C:\Python34\lib\threading.py", line 921, in _bootstrap_inner
    self.run()
  File "C:\Python34\lib\threading.py", line 869, in run
    self._target(*self._args, **self._kwargs)
  File "C:\Python34\lib\subprocess.py", line 1170, in _readerthread
    buffer.append(fh.read())
  File "C:\Python34\lib\encodings\cp1252.py", line 23, in decode
    return codecs.charmap_decode(input,self.errors,decoding_table)[0]
UnicodeDecodeError: 'charmap' codec can't decode byte 0x81 in position 27: character maps to <undefined>

我怎样才能解决这个问题？

Answer 1

univeral_newlines=True启用文本模式。子进程输出（字节）使用解码locale.getpreferredencoding(False)字符编码进行解码，如@cdosborn 提到的。

如果不起作用，请提供encoding所使用的实际值command。和/或指定错误处理程序，例如'ignore'、'surrogateescape'等 作为errors参数：

from subprocess import Popen, PIPE

def __executeCommand(self, command: str, input: str = None, 
                     encoding=None, errors='strict') -> str:
    text_mode = (encoding is None)
    with Popen(command, stdout=PIPE, stderr=PIPE, stdin=PIPE,
               universal_newlines=text_mode) as p:
        if input is not None and not text_mode:
            input = input.encode(encoding, errors) # convert to bytes
        output, err = p.communicate(input)
    if err or p.returncode != 0: 
        raise EnvironmentError("Could not generate the key. "
                               "Error: {}, Return Value: {}".format(
                                   ascii(err), p.returncode))
    return output if text_mode else output.decode(encoding, errors)