python在windows下UnicodeDecodeError的解决方法

之前在windows下使用python调用某些模块时都会报错，像这样：

C:\Documents and Settings\Administrator>python -m CGIHTTPServer
Traceback (most recent call last):
  File "C:\Python27\lib\runpy.py", line 162, in _run_module_as_main
    "__main__", fname, loader, pkg_name)
  File "C:\Python27\lib\runpy.py", line 72, in _run_code
    exec code in run_globals
  File "C:\Python27\lib\CGIHTTPServer.py", line 30, 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 SimpleHTTPRequestHand
ler
    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 0xd7 in position 9: ordinal
not in range(128)

可以看到栈跟踪一直指向了python目录下的lib\mimetypes.py文件，根据查到的资料，解决方法是这样的

找到mimetypes.py文件第256行左右的default_encoding = sys.getdefaultencoding()，在它的前面加上

if sys.getdefaultencoding() != 'gbk': 
            reload(sys) 
            sys.setdefaultencoding('gbk')  

if和default_encoding对齐，然后问题就解决了，详细原理等我深入了解了再补充过来