diff -r 401e8882baf9 Doc/library/wsgiref.rst
--- a/Doc/library/wsgiref.rst	Sun Mar 06 12:24:49 2011 +0100
+++ b/Doc/library/wsgiref.rst	Sun Mar 06 13:29:49 2011 +0000
@@ -184,7 +184,7 @@
 manipulation of WSGI response headers using a mapping-like interface.
 
 
-.. class:: Headers(headers)
+.. class:: Headers([headers])
 
    Create a mapping-like object wrapping *headers*, which must be a list of header
    name/value tuples as described in :pep:`3333`.
diff -r 401e8882baf9 Lib/test/test_wsgiref.py
--- a/Lib/test/test_wsgiref.py	Sun Mar 06 12:24:49 2011 +0100
+++ b/Lib/test/test_wsgiref.py	Sun Mar 06 13:29:49 2011 +0000
@@ -28,7 +28,6 @@
         self.server_port = port
         self.setup_environ()
 
-
 class MockHandler(WSGIRequestHandler):
     """Non-socket HTTP handler"""
     def setup(self):
@@ -38,10 +37,6 @@
     def finish(self):
         pass
 
-
-
-
-
 def hello_app(environ,start_response):
     start_response("200 OK", [
         ('Content-Type','text/plain'),
@@ -63,28 +58,6 @@
 
     return out.getvalue(), err.getvalue()
 
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
 def compare_generic_iter(make_it,match):
     """Utility to compare a generic 2.1/2.2+ iterator with an iterable
 
@@ -121,11 +94,6 @@
         else:
             raise AssertionError("Too many items from .__next__()", it)
 
-
-
-
-
-
 class IntegrationTests(TestCase):
 
     def check_hello(self, out, has_length=True):
@@ -373,14 +341,15 @@
 
     def testMappingInterface(self):
         test = [('x','y')]
-        self.assertEqual(len(Headers([])),0)
-        self.assertEqual(len(Headers(test[:])),1)
+        self.assertEqual(len(Headers()), 0)
+        self.assertEqual(len(Headers([])), 0)
+        self.assertEqual(len(Headers(test[:])), 1)
         self.assertEqual(Headers(test[:]).keys(), ['x'])
         self.assertEqual(Headers(test[:]).values(), ['y'])
         self.assertEqual(Headers(test[:]).items(), test)
         self.assertFalse(Headers(test).items() is test)  # must be copy!
 
-        h=Headers([])
+        h=Headers()
         del h['foo']   # should not raise an error
 
         h['Foo'] = 'bar'
@@ -405,9 +374,8 @@
     def testRequireList(self):
         self.assertRaises(TypeError, Headers, "foo")
 
-
     def testExtras(self):
-        h = Headers([])
+        h = Headers()
         self.assertEqual(str(h),'\r\n')
 
         h.add_header('foo','bar',baz="spam")
@@ -445,16 +413,6 @@
     def handle_error(self):
         raise   # for testing, we want to see what's happening
 
-
-
-
-
-
-
-
-
-
-
 class HandlerTests(TestCase):
 
     def checkEnvironAttrs(self, handler):
@@ -504,7 +462,6 @@
             self.assertRaises(NotImplementedError, getattr(h,name))
         self.assertRaises(NotImplementedError, h._write, "test")
 
-
     def testContentLength(self):
         # Demo one reason iteration is better than write()...  ;)
 
@@ -596,7 +553,6 @@
             "\r\n".encode("iso-8859-1")+MSG))
         self.assertIn("AssertionError", h.stderr.getvalue())
 
-
     def testHeaderFormats(self):
 
         def non_error_app(e,s):
diff -r 401e8882baf9 Lib/wsgiref/headers.py
--- a/Lib/wsgiref/headers.py	Sun Mar 06 12:24:49 2011 +0100
+++ b/Lib/wsgiref/headers.py	Sun Mar 06 13:29:49 2011 +0000
@@ -24,12 +24,11 @@
     else:
         return param
 
-
 class Headers:
-
     """Manage a collection of HTTP response headers"""
 
-    def __init__(self,headers):
+    def __init__(self, headers=None):
+        headers = headers if headers is not None else []
         if type(headers) is not list:
             raise TypeError("Headers must be a list of name/value tuples")
         self._headers = headers
@@ -55,7 +54,7 @@
         self._headers.append(
             (self._convert_string_type(name), self._convert_string_type(val)))
 
-    def __delitem__(self,name):
+    def __delitem__(self, name):
         """Delete all occurrences of a header, if present.
 
         Does *not* raise an exception if the header is missing.
@@ -63,7 +62,7 @@
         name = self._convert_string_type(name.lower())
         self._headers[:] = [kv for kv in self._headers if kv[0].lower() != name]
 
-    def __getitem__(self,name):
+    def __getitem__(self, name):
         """Get the first header value for 'name'
 
         Return None if the header is missing instead of raising an exception.
@@ -78,7 +77,6 @@
         """Return true if the message contains the header."""
         return self.get(name) is not None
 
-
     def get_all(self, name):
         """Return a list of all the values for the named field.
 
@@ -88,18 +86,16 @@
         If no fields exist with the given name, returns an empty list.
         """
         name = self._convert_string_type(name.lower())
-        return [kv[1] for kv in self._headers if kv[0].lower()==name]
+        return [v for k, v in self._headers if k.lower() == name]
 
-
-    def get(self,name,default=None):
+    def get(self, name, default=None):
         """Get the first header value for 'name', or return 'default'"""
         name = self._convert_string_type(name.lower())
-        for k,v in self._headers:
+        for k, v in self._headers:
             if k.lower()==name:
                 return v
         return default
 
-
     def keys(self):
         """Return a list of all the header field names.
 
@@ -141,7 +137,7 @@
     def __bytes__(self):
         return str(self).encode('iso-8859-1')
 
-    def setdefault(self,name,value):
+    def setdefault(self, name, value):
         """Return first matching header value for 'name', or 'value'
 
         If there is no header named 'name', add a new header with name 'name'