diff -r f80d5faa60ee Doc/library/xml.sax.rst
--- a/Doc/library/xml.sax.rst	Fri Apr 03 11:09:08 2015 +0200
+++ b/Doc/library/xml.sax.rst	Fri Apr 03 12:25:06 2015 +0300
@@ -47,7 +47,11 @@ The convenience functions are:
 .. function:: parseString(string, handler, error_handler=handler.ErrorHandler())
 
    Similar to :func:`parse`, but parses from a buffer *string* received as a
-   parameter.
+   parameter.  *string* must be a :class:`str` instance or a
+   :term:`bytes-like object`.
+
+   .. versionchanged:: 3.5
+      Added support of :class:`str` instances.
 
 A typical SAX application uses three kinds of objects: readers, handlers and
 input sources.  "Reader" in this context is another term for parser, i.e. some
diff -r f80d5faa60ee Lib/test/test_nntplib.py
--- a/Lib/test/test_nntplib.py	Fri Apr 03 11:09:08 2015 +0200
+++ b/Lib/test/test_nntplib.py	Fri Apr 03 12:25:06 2015 +0300
@@ -1509,15 +1509,15 @@ class MockSocketTests(unittest.TestCase)
             Handler, nntplib.NNTPPermanentError, authinfo_response,
             login, password)
 
-if ssl is not None:
-    class MockSslTests(MockSocketTests):
-        class nntp_class(nntplib.NNTP_SSL):
-            def __init__(self, *pos, **kw):
-                class bypass_context:
-                    """Bypass encryption and actual SSL module"""
-                    def wrap_socket(sock, **args):
-                        return sock
-                return super().__init__(*pos, ssl_context=bypass_context, **kw)
+class bypass_context:
+    """Bypass encryption and actual SSL module"""
+    def wrap_socket(sock, **args):
+        return sock
+
+@unittest.skipUnless(ssl, 'requires SSL support')
+class MockSslTests(MockSocketTests):
+    def nntp_class(self, *pos, **kw):
+        return nntplib.NNTP_SSL(*pos, ssl_context=bypass_context, **kw)
 
 
 if __name__ == "__main__":
diff -r f80d5faa60ee Lib/test/test_sax.py
--- a/Lib/test/test_sax.py	Fri Apr 03 11:09:08 2015 +0200
+++ b/Lib/test/test_sax.py	Fri Apr 03 12:25:06 2015 +0300
@@ -200,6 +200,13 @@ class ParseTest(unittest.TestCase):
         parseString(s, XMLGenerator(result, 'utf-8'))
         self.assertEqual(result.getvalue(), xml_str(self.data, 'utf-8'))
 
+    def test_parseString_text(self):
+        encodings = ('us-ascii', 'iso-8859-1', 'utf-8',
+                     'utf-16', 'utf-16le', 'utf-16be')
+        for encoding in encodings:
+            self.check_parseString(xml_str(self.data, encoding))
+        self.check_parseString(self.data)
+
     def test_parseString_bytes(self):
         # UTF-8 is default encoding, US-ASCII is compatible with UTF-8,
         # UTF-16 is autodetected
diff -r f80d5faa60ee Lib/xml/sax/__init__.py
--- a/Lib/xml/sax/__init__.py	Fri Apr 03 11:09:08 2015 +0200
+++ b/Lib/xml/sax/__init__.py	Fri Apr 03 12:25:06 2015 +0300
@@ -33,8 +33,7 @@ def parse(source, handler, errorHandler=
     parser.parse(source)
 
 def parseString(string, handler, errorHandler=ErrorHandler()):
-    from io import BytesIO
-
+    import io
     if errorHandler is None:
         errorHandler = ErrorHandler()
     parser = make_parser()
@@ -42,7 +41,10 @@ def parseString(string, handler, errorHa
     parser.setErrorHandler(errorHandler)
 
     inpsrc = InputSource()
-    inpsrc.setByteStream(BytesIO(string))
+    if isinstance(string, str):
+        inpsrc.setCharacterStream(io.StringIO(string))
+    else:
+        inpsrc.setByteStream(io.BytesIO(string))
     parser.parse(inpsrc)
 
 # this is the parser list used by the make_parser function if no
diff -r f80d5faa60ee Misc/NEWS
--- a/Misc/NEWS	Fri Apr 03 11:09:08 2015 +0200
+++ b/Misc/NEWS	Fri Apr 03 12:25:06 2015 +0300
@@ -16,6 +16,8 @@ Core and Builtins
 Library
 -------
 
+- Issue #10590: xml.sax.parseString() now supports string argument.
+
 - Issue #2175: SAX parsers now support a character stream of InputSource object.
 
 - Issue #16840: Tkinter now supports 64-bit integers added in Tcl 8.4 and