python2.7中的UnicodeDecodeError: 'ascii' codec can't decode byte 0xb0 in position 1: ordinal not in ra

在学习写一个简单的http服务器中报的错。

Traceback (most recent call last):
  File "httpservice.py", line 5, in <module>
    import SimpleHTTPServer
  File "C:\Python27\lib\SimpleHTTPServer.py", line 27, in <module>
    class SimpleHTTPRequestHandler(BaseHTTPServer.BaseHTTPRequestHandler):
  File "C:\Python27\lib\SimpleHTTPServer.py", line 208, in SimpleHTTPRequestHandler
    mimetypes.init() # try to read system mime.types
  File "C:\Python27\lib\mimetypes.py", line 358, in init
    db.read_windows_registry()
  File "C:\Python27\lib\mimetypes.py", line 258, in read_windows_registry
    for subkeyname in enum_types(hkcr):
  File "C:\Python27\lib\mimetypes.py", line 249, in enum_types
    ctype = ctype.encode(default_encoding) # omit in 3.x!
UnicodeDecodeError: 'ascii' codec can't decode byte 0xb0 in position 1: ordinal not in range(128)

原因：

参考http://stackoverflow.com/questions/4237898/unicodedecodeerror-ascii-codec-cant-decode-byte-0xe0-in-position-0-ordinal

python27中的bug

This is a bug in mimetypes, triggered by bad data in the registry. (рєфшю/AMR is not at all a valid MIME media type.)

ctype is a registry key name returned by _winreg.EnumKey, which mimetypes is expecting to be a Unicode string, but it isn't. Unlike _winreg.QueryValueEx, EnumKey returns a byte string (direct from the ANSI version of the Windows API; _winreg in Python 2 doesn't use the Unicode interfaces even though it returns Unicode strings, so it'll never read non-ANSI characters correctly).

So the attempt to .encode it fails with a Unicode​Decode​Error trying to get a Unicode string before encoding it back to ASCII!

解决方法：

修改默认的编码方式

import sys
reload(sys)
sys.setdefaultencoding('gb18030')