Python2.7在Windows上有一个bug，运行报错：

UnicodeDecodeError: 'ascii' codec can't decode byte 0xc4 in position 33: ordinal not in range(128)

解决方案如下：

编辑Python27\Lib\mimetypes.py文件，全选，替换为以下patch后的正确脚本，或者直接依据此patch修改：

"""Guess the MIME type of a file. This module defines two useful functions: guess_type(url, strict=1) -- guess the MIME type and encoding of a URL. guess_extension(type, strict=1) -- guess the extension for a given MIME type. It also contains the following, for tuning the behavior: Data: knownfiles -- list of files to parseinited -- flag set when init() has been calledsuffix_map -- dictionary mapping suffixes to suffixesencodings_map -- dictionary mapping suffixes to encodingstypes_map -- dictionary mapping suffixes to types Functions: init([files]) -- parse a list of files, default knownfiles (on Windows, the default values are taken from the registry)read_mime_types(file) -- parse one file, return a dictionary or None"""from itertools import count import osimport sysimport posixpathimport urllibtry: import _winregexcept ImportError: _winreg = None __all__ = [ "guess_type","guess_extension","guess_all_extensions", "add_type","read_mime_types","init"] knownfiles = [ "/etc/mime.types", "/etc/httpd/mime.types", # Mac OS X "/etc/httpd/conf/mime.types", # Apache "/etc/apache/mime.types", # Apache 1 "/etc/apache2/mime.types", # Apache 2 "/usr/local/etc/httpd/conf/mime.types", "/usr/local/lib/netscape/mime.types", "/usr/local/etc/httpd/conf/mime.types", # Apache 1.2 "/usr/local/etc/mime.types", # Apache 1.3 ] inited = False_db = None class MimeTypes: """MIME-types datastore. This datastore can handle information from mime.types-style files and supports basic determination of MIME type from a filename or URL, and can guess a reasonable extension given a MIME type. """ def __init__(self, filenames=(), strict=True): if not inited: init() self.encodings_map = encodings_map.copy() self.suffix_map = suffix_map.copy() self.types_map = ({}, {}) # dict for (non-strict, strict) self.types_map_inv = ({}, {}) for (ext, type) in types_map.items(): self.add_type(type, ext, True) for (ext, type) in common_types.items(): self.add_type(type, ext, False) for name in filenames: self.read(name, strict) def add_type(self, type, ext, strict=True): """Add a mapping between a type and an extension. When the extension is already known, the new type will replace the old one. When the type is already known the extension will be added to the list of known extensions. If strict is true, information will be added to list of standard types, else to the list of non-standard types. """ self.types_map[strict][ext] = type exts = self.types_map_inv[strict].setdefault(type, []) if ext not in exts: exts.append(ext) def guess_type(self, url, strict=True): """Guess the type of a file based on its URL. Return value is a tuple (type, encoding) where type is None if the type can't be guessed (no or unknown suffix) or a string of the form type/subtype, usable for a MIME Content-type header; and encoding is None for no encoding or the name of the program used to encode (e.g. compress or gzip). The mappings are table driven. Encoding suffixes are case sensitive; type suffixes are first tried case sensitive, then case insensitive. The suffixes .tgz, .taz and .tz (case sensitive!) are all mapped to '.tar.gz'. (This is table-driven too, using the dictionary suffix_map.) Optional `strict' argument when False adds a bunch of commonly found, but non-standard types. """ scheme, url = urllib.splittype(url) if scheme == 'data': # syntax of data URLs: # dataurl := "data:" [ mediatype ] [ ";base64" ] "," data # mediatype := [ type "/" subtype ] *( ";" parameter ) # data := *urlchar # parameter := attribute "=" value # type/subtype defaults to "text/plain" comma = url.find(',') if comma < 0: # bad data URL return None, None semi = url.find(';', 0, comma) if semi >= 0: type = url[:semi] else: type = url[:comma] if '=' in type or '/' not in type: type = 'text/plain' return type, None # never compressed, so encoding is None base, ext = posixpath.splitext(url) while ext in self.suffix_map: base, ext = posixpath.splitext(base + self.suffix_map[ext]) if ext in self.encodings_map: encoding = self.encodings_map[ext] base, ext = posixpath.splitext(base) else: encoding = None types_map = self.types_map[True] if ext in types_map: return types_map[ext], encoding elif ext.lower() in types_map: return types_map[ext.lower()], encoding elif strict: return None, encoding types_map = self.types_map[False] if ext in types_map: return types_map[ext], encoding elif ext.lower() in types_map: return types_map[ext.lower()], encoding else: return None, encoding def guess_all_extensions(self, type, strict=True): """Guess the extensions for a file based on its MIME type. Return value is a list of strings giving the possible filename extensions, including the leading dot ('.'). The extension is not guaranteed to have been associated with any particular data stream, but would be mapped to the MIME type `type' by guess_type(). Optional `strict' argument when false adds a bunch of commonly found, but non-standard types. """ type = type.lower() extensions = self.types_map_inv[True].get(type, []) if not strict: for ext in self.types_map_inv[False].get(type, []): if ext not in extensions: extensions.append(ext) return extensions def guess_extension(self, type, strict=True): """Guess the extension for a file based on its MIME type. Return value is a string giving a filename extension, including the leading dot ('.'). The extension is not guaranteed to have been associated with any particular data stream, but would be mapped to the MIME type `type' by guess_type(). If no extension can be guessed for `type', None is returned. Optional `strict' argument when false adds a bunch of commonly found, but non-standard types. """ extensions = self.guess_all_extensions(type, strict) if not extensions: return None return extensions[0] def read(self, filename, strict=True): """ Read a single mime.types-format file, specified by pathname. If strict is true, information will be added to list of standard types, else to the list of non-standard types. """ with open(filename) as fp: self.readfp(fp, strict) def readfp(self, fp, strict=True): """ Read a single mime.types-format file. If strict is true, information will be added to list of standard types, else to the list of non-standard types. """ while 1: line = fp.readline() if not line: break words = line.split() for i in range(len(words)): if words[i][0] == '#': del words[i:] break if not words: continue type, suffixes = words[0], words[1:] for suff in suffixes: self.add_type(type, '.' + suff, strict) def read_windows_registry(self, strict=True): """ Load the MIME types database from Windows registry. If strict is true, information will be added to list of standard types, else to the list of non-standard types. """ # Windows only if not _winreg: return def enum_types(mimedb): for i in count(): try: yield _winreg.EnumKey(mimedb, i) except EnvironmentError: break default_encoding = sys.getdefaultencoding() with _winreg.OpenKey(_winreg.HKEY_CLASSES_ROOT, '') as hkcr: for subkeyname in enum_types(hkcr): try: with _winreg.OpenKey(hkcr, subkeyname) as subkey: # Only check file extensions if not subkeyname.startswith("."): continue # raises EnvironmentError if no 'Content Type' value mimetype, datatype = _winreg.QueryValueEx( subkey, 'Content Type') if datatype != _winreg.REG_SZ: continue try: mimetype = mimetype.encode(default_encoding) subkeyname = subkeyname.encode(default_encoding) except UnicodeEncodeError: continue self.add_type(mimetype, subkeyname, strict) except EnvironmentError: continue def guess_type(url, strict=True): """Guess the type of a file based on its URL. Return value is a tuple (type, encoding) where type is None if the type can't be guessed (no or unknown suffix) or a string of the form type/subtype, usable for a MIME Content-type header; and encoding is None for no encoding or the name of the program used to encode (e.g. compress or gzip). The mappings are table driven. Encoding suffixes are case sensitive; type suffixes are first tried case sensitive, then case insensitive. The suffixes .tgz, .taz and .tz (case sensitive!) are all mapped to ".tar.gz". (This is table-driven too, using the dictionary suffix_map). Optional `strict' argument when false adds a bunch of commonly found, but non-standard types. """ if _db is None: init() return _db.guess_type(url, strict) def guess_all_extensions(type, strict=True): """Guess the extensions for a file based on its MIME type. Return value is a list of strings giving the possible filename extensions, including the leading dot ('.'). The extension is not guaranteed to have been associated with any particular data stream, but would be mapped to the MIME type `type' by guess_type(). If no extension can be guessed for `type', None is returned. Optional `strict' argument when false adds a bunch of commonly found, but non-standard types. """ if _db is None: init() return _db.guess_all_extensions(type, strict) def guess_extension(type, strict=True): """Guess the extension for a file based on its MIME type. Return value is a string giving a filename extension, including the leading dot ('.'). The extension is not guaranteed to have been associated with any particular data stream, but would be mapped to the MIME type `type' by guess_type(). If no extension can be guessed for `type', None is returned. Optional `strict' argument when false adds a bunch of commonly found, but non-standard types. """ if _db is None: init() return _db.guess_extension(type, strict) def add_type(type, ext, strict=True): """Add a mapping between a type and an extension. When the extension is already known, the new type will replace the old one. When the type is already known the extension will be added to the list of known extensions. If strict is true, information will be added to list of standard types, else to the list of non-standard types. """ if _db is None: init() return _db.add_type(type, ext, strict) def init(files=None): global suffix_map, types_map, encodings_map, common_types global inited, _db inited = True # so that MimeTypes.__init__() doesn't call us again db = MimeTypes() if files is None: if _winreg: db.read_windows_registry() files = knownfiles for file in files: if os.path.isfile(file): db.read(file) encodings_map = db.encodings_map suffix_map = db.suffix_map types_map = db.types_map[True] common_types = db.types_map[False] # Make the DB a global variable now that it is fully initialized _db = db def read_mime_types(file): try: f = open(file) except IOError: return None db = MimeTypes() db.readfp(f, True) return db.types_map[True] def _default_mime_types(): global suffix_map global encodings_map global types_map global common_types suffix_map = { '.tgz': '.tar.gz', '.taz': '.tar.gz', '.tz': '.tar.gz', '.tbz2': '.tar.bz2', '.txz': '.tar.xz', } encodings_map = { '.gz': 'gzip', '.Z': 'compress', '.bz2': 'bzip2', '.xz': 'xz', } # Before adding new types, make sure they are either registered with IANA, # at http://mon, but non-standard types. --extension / -e -- guess extension instead of type More than one type argument may be given.""" def usage(code, msg=''): print USAGE if msg: print msg sys.exit(code) try: opts, args = getopt.getopt(sys.argv[1:], 'hle', ['help', 'lenient', 'extension']) except getopt.error, msg: usage(1, msg) strict = 1 extension = 0 for opt, arg in opts: if opt in ('-h', '--help'): usage(0) elif opt in ('-l', '--lenient'): strict = 0 elif opt in ('-e', '--extension'): extension = 1 for gtype in args: if extension: guess = guess_extension(gtype, strict) if not guess: print "I don't know anything about type", gtype else: print guess else: guess, encoding = guess_type(gtype, strict) if not guess: print "I don't know anything about type", gtype else: print 'type:', guess, 'encoding:', encoding

附上一篇关于python编码的帖子

1. pyhton的所有内置库、方法接受的是unicode编码的字符串。

2. str.decode 函数就是转成unicode编码，所以能decode的字符串传进python的内置库、函数都能正确运行。

3.问题在于这个decode函数解码时到底要传哪个参数：utf-8,gbk,gb2312......等N种编码。参数不当，就会抛类似异常：

复制代码 代码如下:UnicodeDecodeError: 'gbk' codec can't decode bytes in position 2-3: illegal multibyte sequence

UnicodeDecodeError: 'utf8' codec can't decode bytes in position 0-1: invalid data

下面举个例子：

#coding:utf-8 #指定本文件编码为utf8 import os # 以下为示例代码，不一定能运行。随意写的，无编译运行过。 # 例子以XP平台为例，因为linux平台编码（UTF-8）与window平台（GBK）不一样。 # 假设D盘下面有很多中文名称文件 filelist = os.listdir(r"d:\\") # 此处返回的list中的中文是以GBK编码的，你可以通过查看cmd窗口属性看到。 for path in filelist: if os.path.isdir(path): continue fp = open(path.decode("GBK") , 'rb') # 如果此处用 path.decode("UTF-8") 就会抛异常，原因是wind的dir命令返回的是GBK编码 print len(fp.read()) fp.close() filepath =r"d:\\中文文件.doc" # 假设此文存在，记得要带中文 fp = open(filepath.decode('utf-8'), "rb") #这里使用utf8参数进行解码，原因是文件头里有句coding: utf-8 print len(fp.read()) fp.close() path2 = u"d:\\中文文件.doc" # 假如这里有个u在前面，这个变量就是unicode编码了，不用解码。 fp = open(path2, 'rb') print len(fp.read()) fp.close()