diff --git a/Lib/urllib/parse.py b/Lib/urllib/parse.py
index 78f3084..ab5b356 100644
--- a/Lib/urllib/parse.py
+++ b/Lib/urllib/parse.py
@@ -60,6 +60,7 @@
                 '0123456789'
                 '+-.')
 
+# XXX: Consider replacing with functools.lru_cache
 MAX_CACHE_SIZE = 20
 _parse_cache = {}
 
@@ -69,66 +70,210 @@
     _safe_quoters.clear()
 
 
-class ResultMixin(object):
-    """Shared methods for the parsed result objects."""
+# Helpers for bytes handling
+# For 3.2, we deliberately require applications that
+# handle improperly quoted URLs to do their own
+# decoding and encoding. If valid use cases are
+# presented, we may relax this by using latin-1
+# decoding internally for 3.3
+_implicit_encoding = 'ascii'
+_implicit_errors = 'strict'
+
+def _noop(obj):
+    return obj
+
+def _encode_result(obj, encoding=_implicit_encoding,
+                        errors=_implicit_errors):
+    return obj.encode(encoding, errors)
+
+def _decode_args(args, encoding=_implicit_encoding,
+                       errors=_implicit_errors):
+    return tuple(x.decode(encoding, errors) if x else '' for x in args)
+
+def _coerce_args(*args):
+    # Invokes decode if necessary to create str args
+    # and returns the coerced inputs along with
+    # an appropriate result coercion function
+    #   - noop for str inputs
+    #   - encoding function otherwise
+    str_input = isinstance(args[0], str)
+    for arg in args[1:]:
+        # We special-case the empty string to support the
+        # "scheme=''" default argument to some functions
+        if arg and isinstance(arg, str) != str_input:
+            raise TypeError("Cannot mix str and non-str arguments")
+    if str_input:
+        return args + (_noop,)
+    return _decode_args(args) + (_encode_result,)
+
+# Result objects are more helpful than simple tuples
+class _ResultMixinStr(object):
+    """Standard approach to encoding parsed results from str to bytes"""
+    __slots__ = ()
+
+    def encode(self, encoding='ascii', errors='strict'):
+        return self._encoded_counterpart(*(x.encode(encoding, errors) for x in self))
+
+
+class _ResultMixinBytes(object):
+    """Standard approach to decoding parsed results from bytes to str"""
+    __slots__ = ()
+
+    def decode(self, encoding='ascii', errors='strict'):
+        return self._decoded_counterpart(*(x.decode(encoding, errors) for x in self))
+
+
+class _NetlocResultMixinBase(object):
+    """Shared methods for the parsed result objects containing a netloc element"""
+    __slots__ = ()
 
     @property
     def username(self):
-        netloc = self.netloc
-        if "@" in netloc:
-            userinfo = netloc.rsplit("@", 1)[0]
-            if ":" in userinfo:
-                userinfo = userinfo.split(":", 1)[0]
-            return userinfo
-        return None
+        return self._userinfo[0]
 
     @property
     def password(self):
-        netloc = self.netloc
-        if "@" in netloc:
-            userinfo = netloc.rsplit("@", 1)[0]
-            if ":" in userinfo:
-                return userinfo.split(":", 1)[1]
-        return None
+        return self._userinfo[1]
 
     @property
     def hostname(self):
-        netloc = self.netloc.split('@')[-1]
-        if '[' in netloc and ']' in netloc:
-            return netloc.split(']')[0][1:].lower()
-        elif ':' in netloc:
-            return netloc.split(':')[0].lower()
-        elif netloc == '':
-            return None
-        else:
-            return netloc.lower()
+        hostname = self._hostinfo[0]
+        if not hostname:
+            hostname = None
+        elif hostname is not None:
+            hostname = hostname.lower()
+        return hostname
 
     @property
     def port(self):
-        netloc = self.netloc.split('@')[-1].split(']')[-1]
-        if ':' in netloc:
-            port = netloc.split(':')[1]
-            return int(port, 10)
+        port = self._hostinfo[1]
+        if port is not None:
+            port = int(port, 10)
+        return port
+
+
+class _NetlocResultMixinStr(_NetlocResultMixinBase, _ResultMixinStr):
+    __slots__ = ()
+
+    @property
+    def _userinfo(self):
+        netloc = self.netloc
+        userinfo, have_info, hostinfo = netloc.rpartition('@')
+        if have_info:
+            username, have_password, password = userinfo.partition(':')
+            if not have_password:
+                password = None
         else:
-            return None
+            username = password = None
+        return username, password
+
+    @property
+    def _hostinfo(self):
+        netloc = self.netloc
+        _, _, hostinfo = netloc.rpartition('@')
+        _, have_open_br, bracketed = hostinfo.partition('[')
+        if have_open_br:
+            hostname, _, port = bracketed.partition(']')
+            _, have_port, port = port.partition(':')
+        else:
+            hostname, have_port, port = hostinfo.partition(':')
+        if not have_port:
+            port = None
+        return hostname, port
+
+
+class _NetlocResultMixinBytes(_NetlocResultMixinBase, _ResultMixinBytes):
+    __slots__ = ()
+
+    @property
+    def _userinfo(self):
+        netloc = self.netloc
+        userinfo, have_info, hostinfo = netloc.rpartition(b'@')
+        if have_info:
+            username, have_password, password = userinfo.partition(b':')
+            if not have_password:
+                password = None
+        else:
+            username = password = None
+        return username, password
+
+    @property
+    def _hostinfo(self):
+        netloc = self.netloc
+        _, _, hostinfo = netloc.rpartition(b'@')
+        _, have_open_br, bracketed = hostinfo.partition(b'[')
+        if have_open_br:
+            hostname, _, port = bracketed.partition(b']')
+            _, have_port, port = port.partition(b':')
+        else:
+            hostname, have_port, port = hostinfo.partition(b':')
+        if not have_port:
+            port = None
+        return hostname, port
+
 
 from collections import namedtuple
 
-class SplitResult(namedtuple('SplitResult', 'scheme netloc path query fragment'), ResultMixin):
+_DefragResultBase = namedtuple('DefragResult', 'url fragment')
+_SplitResultBase = namedtuple('SplitResult', 'scheme netloc path query fragment')
+_ParseResultBase = namedtuple('ParseResult', 'scheme netloc path params query fragment')
 
+# For backwards compatibility, alias _NetlocResultMixinStr
+# ResultBase is no longer part of the documented API, but it is
+# retained since deprecating it isn't worth the hassle
+ResultBase = _NetlocResultMixinStr
+
+# Structured result objects for string data
+class DefragResult(_DefragResultBase, _ResultMixinStr):
     __slots__ = ()
+    def geturl(self):
+        if self.fragment:
+            return self.url + '#' + self.fragment
+        else:
+            return self.url
 
+class SplitResult(_SplitResultBase, _NetlocResultMixinStr):
+    __slots__ = ()
     def geturl(self):
         return urlunsplit(self)
 
-
-class ParseResult(namedtuple('ParseResult', 'scheme netloc path params query fragment'), ResultMixin):
-
+class ParseResult(_ParseResultBase, _NetlocResultMixinStr):
     __slots__ = ()
-
     def geturl(self):
         return urlunparse(self)
 
+# Structured result objects for bytes data
+class DefragResultBytes(_DefragResultBase, _ResultMixinBytes):
+    __slots__ = ()
+    def geturl(self):
+        if self.fragment:
+            return self.url + b'#' + self.fragment
+        else:
+            return self.url
+
+class SplitResultBytes(_SplitResultBase, _NetlocResultMixinBytes):
+    __slots__ = ()
+    def geturl(self):
+        return urlunsplit(self)
+
+class ParseResultBytes(_ParseResultBase, _NetlocResultMixinBytes):
+    __slots__ = ()
+    def geturl(self):
+        return urlunparse(self)
+
+# Set up the encode/decode result pairs
+def _fix_result_transcoding():
+    _result_pairs = (
+        (DefragResult, DefragResultBytes),
+        (SplitResult, SplitResultBytes),
+        (ParseResult, ParseResultBytes),
+    )
+    for _decoded, _encoded in _result_pairs:
+        _decoded._encoded_counterpart = _encoded
+        _encoded._decoded_counterpart = _decoded
+
+_fix_result_transcoding()
+del _fix_result_transcoding
 
 def urlparse(url, scheme='', allow_fragments=True):
     """Parse a URL into 6 components:
@@ -136,13 +281,15 @@
     Return a 6-tuple: (scheme, netloc, path, params, query, fragment).
     Note that we don't break the components up in smaller bits
     (e.g. netloc is a single string) and we don't expand % escapes."""
+    url, scheme, _coerce_result = _coerce_args(url, scheme)
     tuple = urlsplit(url, scheme, allow_fragments)
     scheme, netloc, url, query, fragment = tuple
     if scheme in uses_params and ';' in url:
         url, params = _splitparams(url)
     else:
         params = ''
-    return ParseResult(scheme, netloc, url, params, query, fragment)
+    result = ParseResult(scheme, netloc, url, params, query, fragment)
+    return _coerce_result(result)
 
 def _splitparams(url):
     if '/'  in url:
@@ -167,11 +314,12 @@
     Return a 5-tuple: (scheme, netloc, path, query, fragment).
     Note that we don't break the components up in smaller bits
     (e.g. netloc is a single string) and we don't expand % escapes."""
+    url, scheme, _coerce_result = _coerce_args(url, scheme)
     allow_fragments = bool(allow_fragments)
     key = url, scheme, allow_fragments, type(url), type(scheme)
     cached = _parse_cache.get(key, None)
     if cached:
-        return cached
+        return _coerce_result(cached)
     if len(_parse_cache) >= MAX_CACHE_SIZE: # avoid runaway growth
         clear_cache()
     netloc = query = fragment = ''
@@ -191,7 +339,7 @@
                 url, query = url.split('?', 1)
             v = SplitResult(scheme, netloc, url, query, fragment)
             _parse_cache[key] = v
-            return v
+            return _coerce_result(v)
         if url.endswith(':') or not url[i+1].isdigit():
             for c in url[:i]:
                 if c not in scheme_chars:
@@ -209,17 +357,18 @@
         url, query = url.split('?', 1)
     v = SplitResult(scheme, netloc, url, query, fragment)
     _parse_cache[key] = v
-    return v
+    return _coerce_result(v)
 
 def urlunparse(components):
     """Put a parsed URL back together again.  This may result in a
     slightly different, but equivalent URL, if the URL that was parsed
     originally had redundant delimiters, e.g. a ? with an empty query
     (the draft states that these are equivalent)."""
-    scheme, netloc, url, params, query, fragment = components
+    scheme, netloc, url, params, query, fragment, _coerce_result = (
+                                                  _coerce_args(*components))
     if params:
         url = "%s;%s" % (url, params)
-    return urlunsplit((scheme, netloc, url, query, fragment))
+    return _coerce_result(urlunsplit((scheme, netloc, url, query, fragment)))
 
 def urlunsplit(components):
     """Combine the elements of a tuple as returned by urlsplit() into a
@@ -227,7 +376,8 @@
     This may result in a slightly different, but equivalent URL, if the URL that
     was parsed originally had unnecessary delimiters (for example, a ? with an
     empty query; the RFC states that these are equivalent)."""
-    scheme, netloc, url, query, fragment = components
+    scheme, netloc, url, query, fragment, _coerce_result = (
+                                          _coerce_args(*components))
     if netloc or (scheme and scheme in uses_netloc and url[:2] != '//'):
         if url and url[:1] != '/': url = '/' + url
         url = '//' + (netloc or '') + url
@@ -237,7 +387,7 @@
         url = url + '?' + query
     if fragment:
         url = url + '#' + fragment
-    return url
+    return _coerce_result(url)
 
 def urljoin(base, url, allow_fragments=True):
     """Join a base URL and a possibly relative URL to form an absolute
@@ -246,32 +396,33 @@
         return url
     if not url:
         return base
+    base, url, _coerce_result = _coerce_args(base, url)
     bscheme, bnetloc, bpath, bparams, bquery, bfragment = \
             urlparse(base, '', allow_fragments)
     scheme, netloc, path, params, query, fragment = \
             urlparse(url, bscheme, allow_fragments)
     if scheme != bscheme or scheme not in uses_relative:
-        return url
+        return _coerce_result(url)
     if scheme in uses_netloc:
         if netloc:
-            return urlunparse((scheme, netloc, path,
-                               params, query, fragment))
+            return _coerce_result(urlunparse((scheme, netloc, path,
+                                              params, query, fragment)))
         netloc = bnetloc
     if path[:1] == '/':
-        return urlunparse((scheme, netloc, path,
-                           params, query, fragment))
+        return _coerce_result(urlunparse((scheme, netloc, path,
+                                          params, query, fragment)))
     if not path:
         path = bpath
         if not params:
             params = bparams
         else:
             path = path[:-1]
-            return urlunparse((scheme, netloc, path,
-                                params, query, fragment))
+            return _coerce_result(urlunparse((scheme, netloc, path,
+                                              params, query, fragment)))
         if not query:
             query = bquery
-        return urlunparse((scheme, netloc, path,
-                           params, query, fragment))
+        return _coerce_result(urlunparse((scheme, netloc, path,
+                                          params, query, fragment)))
     segments = bpath.split('/')[:-1] + path.split('/')
     # XXX The stuff below is bogus in various ways...
     if segments[-1] == '.':
@@ -293,8 +444,8 @@
         segments[-1] = ''
     elif len(segments) >= 2 and segments[-1] == '..':
         segments[-2:] = ['']
-    return urlunparse((scheme, netloc, '/'.join(segments),
-                       params, query, fragment))
+    return _coerce_result(urlunparse((scheme, netloc, '/'.join(segments),
+                                      params, query, fragment)))
 
 def urldefrag(url):
     """Removes any existing fragment from URL.
@@ -303,12 +454,14 @@
     the URL contained no fragments, the second element is the
     empty string.
     """
+    url, _coerce_result = _coerce_args(url)
     if '#' in url:
         s, n, p, a, q, frag = urlparse(url)
         defrag = urlunparse((s, n, p, a, q, ''))
-        return defrag, frag
     else:
-        return url, ''
+        frag = ''
+        defrag = url
+    return _coerce_result(DefragResult(defrag, frag))
 
 def unquote_to_bytes(string):
     """unquote_to_bytes('abc%20def') -> b'abc def'."""
@@ -420,6 +573,7 @@
 
     Returns a list, as G-d intended.
     """
+    qs, _coerce_result = _coerce_args(qs)
     pairs = [s2 for s1 in qs.split('&') for s2 in s1.split(';')]
     r = []
     for name_value in pairs:
@@ -435,10 +589,9 @@
             else:
                 continue
         if len(nv[1]) or keep_blank_values:
-            name = unquote(nv[0].replace('+', ' '))
-            value = unquote(nv[1].replace('+', ' '))
+            name = _coerce_result(unquote(nv[0].replace('+', ' ')))
+            value = _coerce_result(unquote(nv[1].replace('+', ' ')))
             r.append((name, value))
-
     return r
 
 def unquote_plus(string, encoding='utf-8', errors='replace'):