From a6dc531063efe3a8d47ff4639729060c72a3688c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A9s=20Delfino?= <adelfino@gmail.com>
Date: Fri, 26 Oct 2018 11:56:57 -0300
Subject: [PATCH] bpo-34789: make xml.sax.make_parser accept iterables of all
 types (GH-9576)

---
 Doc/library/xml.sax.rst                       |  5 +++-
 Lib/test/test_sax.py                          | 28 +++++++++++++++++++
 Lib/xml/sax/__init__.py                       |  8 +++---
 .../2018-09-25-15-48-50.bpo-34789.rPOEj5.rst  |  2 ++
 4 files changed, 38 insertions(+), 5 deletions(-)
 create mode 100644 Misc/NEWS.d/next/Library/2018-09-25-15-48-50.bpo-34789.rPOEj5.rst

diff --git a/Doc/library/xml.sax.rst b/Doc/library/xml.sax.rst
index aa3ea9bfc55a98..0b6973b8c8a8b3 100644
--- a/Doc/library/xml.sax.rst
+++ b/Doc/library/xml.sax.rst
@@ -40,10 +40,13 @@ The convenience functions are:
 
    Create and return a SAX :class:`~xml.sax.xmlreader.XMLReader` object.  The
    first parser found will
-   be used.  If *parser_list* is provided, it must be a sequence of strings which
+   be used.  If *parser_list* is provided, it must be an iterable of strings which
    name modules that have a function named :func:`create_parser`.  Modules listed
    in *parser_list* will be used before modules in the default list of parsers.
 
+   .. versionchanged:: 3.8
+      The *parser_list* argument can be any iterable, not just a list.
+
 
 .. function:: parse(filename_or_stream, handler, error_handler=handler.ErrorHandler())
 
diff --git a/Lib/test/test_sax.py b/Lib/test/test_sax.py
index 3044960a0ed165..894d86ac71f03c 100644
--- a/Lib/test/test_sax.py
+++ b/Lib/test/test_sax.py
@@ -254,6 +254,34 @@ def test_make_parser2(self):
         from xml.sax import make_parser
         p = make_parser()
 
+    def test_make_parser3(self):
+        # Testing that make_parser can handle different types of
+        # iterables.
+        make_parser(['module'])
+        make_parser(('module', ))
+        make_parser({'module'})
+        make_parser(frozenset({'module'}))
+        make_parser({'module': None})
+        make_parser(iter(['module']))
+
+    def test_make_parser4(self):
+        # Testing that make_parser can handle empty iterables.
+        make_parser([])
+        make_parser(tuple())
+        make_parser(set())
+        make_parser(frozenset())
+        make_parser({})
+        make_parser(iter([]))
+
+    def test_make_parser5(self):
+        # Testing that make_parser can handle iterables with more than
+        # one item.
+        make_parser(['module1', 'module2'])
+        make_parser(('module1', 'module2'))
+        make_parser({'module1', 'module2'})
+        make_parser(frozenset({'module1', 'module2'}))
+        make_parser({'module1': None, 'module2': None})
+        make_parser(iter(['module1', 'module2']))
 
 # ===========================================================================
 #
diff --git a/Lib/xml/sax/__init__.py b/Lib/xml/sax/__init__.py
index 13f6cf58d0d2f2..a0f5d40b2000ce 100644
--- a/Lib/xml/sax/__init__.py
+++ b/Lib/xml/sax/__init__.py
@@ -67,15 +67,15 @@ def parseString(string, handler, errorHandler=ErrorHandler()):
     default_parser_list = sys.registry.getProperty(_key).split(",")
 
 
-def make_parser(parser_list = []):
+def make_parser(parser_list=()):
     """Creates and returns a SAX parser.
 
     Creates the first parser it is able to instantiate of the ones
-    given in the list created by doing parser_list +
-    default_parser_list.  The lists must contain the names of Python
+    given in the iterable created by chaining parser_list and
+    default_parser_list.  The iterables must contain the names of Python
     modules containing both a SAX parser and a create_parser function."""
 
-    for parser_name in parser_list + default_parser_list:
+    for parser_name in list(parser_list) + default_parser_list:
         try:
             return _create_parser(parser_name)
         except ImportError as e:
diff --git a/Misc/NEWS.d/next/Library/2018-09-25-15-48-50.bpo-34789.rPOEj5.rst b/Misc/NEWS.d/next/Library/2018-09-25-15-48-50.bpo-34789.rPOEj5.rst
new file mode 100644
index 00000000000000..28f15c3f41225f
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2018-09-25-15-48-50.bpo-34789.rPOEj5.rst
@@ -0,0 +1,2 @@
+:func:`xml.sax.make_parser` now accepts any iterable as its *parser_list*
+argument.  Patch by Andrés Delfino.