#6423 has_key -> in

Doc/library/cgi.rst

@@ -91,12 +91,13 @@ form contents from standard input or the environment (depending on the value of
 various environment variables set according to the CGI standard).  Since it may
 consume standard input, it should be instantiated only once.
 
-The :class:`FieldStorage` instance can be indexed like a Python dictionary, and
-also supports the standard dictionary methods :meth:`has_key` and :meth:`keys`.
-The built-in :func:`len` is also supported.  Form fields containing empty
-strings are ignored and do not appear in the dictionary; to keep such values,
-provide a true value for the optional *keep_blank_values* keyword parameter when
-creating the :class:`FieldStorage` instance.
+The :class:`FieldStorage` instance can be indexed like a Python dictionary.
+It allows membership testing with the :keyword:`in` operator, and also supports
+the standard dictionary method :meth:`keys` and the built-in function
+:func:`len`.  Form fields containing empty strings are ignored and do not appear
+in the dictionary; to keep such values, provide a true value for the optional
+*keep_blank_values* keyword parameter when creating the :class:`FieldStorage`
+instance.
 
 For instance, the following code (which assumes that the
 :mailheader:`Content-Type` header and blank line have already been printed)
@@ -104,7 +105,7 @@ checks that the fields ``name`` and ``addr`` are both set to a non-empty
 string::
 
    form = cgi.FieldStorage()
-   if not (form.has_key("name") and form.has_key("addr")):
+   if "name" not in form or "addr" not in form:
        print "<H1>Error</H1>"
        print "Please fill in the name and addr fields."
        return