Changed the csv.reader() fileobj argument to interable. This give us

much more flexibility in processing filtered data.
Made the example excel dialect match the dialect in csv.py.
Added explanation of doublequote.
Added explanation of csv.QUOTE_NONE.

pep-0305.txt

@@ -89,11 +89,11 @@ Module Interface
 The module supports two basic APIs, one for reading and one for
 writing.  The basic reading interface is::
 
-    obj = reader(fileobj [, dialect='excel2000']
+    obj = reader(iterable [, dialect='excel2000']
                  [optional keyword args])
 
-A reader object is an iterable which takes a file-like object opened
-for reading as the sole required parameter.  The optional dialect
+A reader object is an iterable which takes an interable object which
+returns lines as the sole required parameter.  The optional dialect
 parameter is discussed below.  It also accepts several optional
 keyword arguments which define specific format settings for the parser
 (see the section "Formatting Parameters").  Readers are typically used
@@ -153,9 +153,10 @@ construct variant dialects by subclassing.  The "excel" dialect is
 implemented as follows::
 
     class excel:
-        quotechar = '"'
         delimiter = ','
+        quotechar = '"'
         escapechar = None
+        doublequote = True
         skipinitialspace = False
         lineterminator = '\r\n'
         quoting = QUOTE_MINIMAL
@@ -188,12 +189,13 @@ parameters are also the keys for the input and output mapping objects
 for the set_dialect() and get_dialect() module functions.
 
 - ``quotechar`` specifies a one-character string to use as the quoting
-  character.  It defaults to '"'.
+  character.  It defaults to '"'.  Setting this to None has the same
+  effect as setting quoting to csv.QUOTE_NONE.
 
 - ``delimiter`` specifies a one-character string to use as the field
   separator.  It defaults to ','.
 
-- ``escapechar`` specifies a one character string used to escape the
+- ``escapechar`` specifies a one-character string used to escape the
   delimiter when quotechar is set to None.
 
 - ``skipinitialspace`` specifies how to interpret whitespace which
@@ -215,7 +217,12 @@ for the set_dialect() and get_dialect() module functions.
     csv.QUOTE_NONNUMERIC means that quotes are always placed around
     fields which contain characters other than [+-0-9.].
 
-- ``doublequote`` (tbd)
+    csv.QUOTE_NONE means that quotes are never placed around
+    fields.
+
+- ``doublequote`` controls the handling of quotes inside fields.  When
+  True two consecutive quotes are interpreted as one during read, and
+  when writing, each quote is written as two quotes.
 
 - are there more to come?