Issue #25985: sys.version_info is now used instead of sys.version
to format short Python version.
diff --git a/Lib/distutils/command/bdist_msi.py b/Lib/distutils/command/bdist_msi.py
index b3cfe9c..f6c21ae 100644
--- a/Lib/distutils/command/bdist_msi.py
+++ b/Lib/distutils/command/bdist_msi.py
@@ -199,7 +199,7 @@
             target_version = self.target_version
             if not target_version:
                 assert self.skip_build, "Should have already checked this"
-                target_version = sys.version[0:3]
+                target_version = '%d.%d' % sys.version_info[:2]
             plat_specifier = ".%s-%s" % (self.plat_name, target_version)
             build = self.get_finalized_command('build')
             build.build_lib = os.path.join(build.build_base,
diff --git a/Lib/distutils/command/bdist_wininst.py b/Lib/distutils/command/bdist_wininst.py
index 0c0e2c1..d3e1d3a 100644
--- a/Lib/distutils/command/bdist_wininst.py
+++ b/Lib/distutils/command/bdist_wininst.py
@@ -141,7 +141,7 @@
             target_version = self.target_version
             if not target_version:
                 assert self.skip_build, "Should have already checked this"
-                target_version = sys.version[0:3]
+                target_version = '%d.%d' % sys.version_info[:2]
             plat_specifier = ".%s-%s" % (self.plat_name, target_version)
             build = self.get_finalized_command('build')
             build.build_lib = os.path.join(build.build_base,
diff --git a/Lib/distutils/command/build.py b/Lib/distutils/command/build.py
index 337dd0b..c6f52e6 100644
--- a/Lib/distutils/command/build.py
+++ b/Lib/distutils/command/build.py
@@ -81,7 +81,7 @@
                             "--plat-name only supported on Windows (try "
                             "using './configure --help' on your platform)")
 
-        plat_specifier = ".%s-%s" % (self.plat_name, sys.version[0:3])
+        plat_specifier = ".%s-%d.%d" % (self.plat_name, *sys.version_info[:2])
 
         # Make it so Python 2.x and Python 2.x with --with-pydebug don't
         # share the same build directories. Doing so confuses the build
@@ -114,7 +114,7 @@
                                            'temp' + plat_specifier)
         if self.build_scripts is None:
             self.build_scripts = os.path.join(self.build_base,
-                                              'scripts-' + sys.version[0:3])
+                                              'scripts-%d.%d' % sys.version_info[:2])
 
         if self.executable is None:
             self.executable = os.path.normpath(sys.executable)
diff --git a/Lib/distutils/command/install.py b/Lib/distutils/command/install.py
index 67db007..9474e9c 100644
--- a/Lib/distutils/command/install.py
+++ b/Lib/distutils/command/install.py
@@ -290,8 +290,8 @@
                             'dist_version': self.distribution.get_version(),
                             'dist_fullname': self.distribution.get_fullname(),
                             'py_version': py_version,
-                            'py_version_short': py_version[0:3],
-                            'py_version_nodot': py_version[0] + py_version[2],
+                            'py_version_short': '%d.%d' % sys.version_info[:2],
+                            'py_version_nodot': '%d%d' % sys.version_info[:2],
                             'sys_prefix': prefix,
                             'prefix': prefix,
                             'sys_exec_prefix': exec_prefix,
diff --git a/Lib/distutils/command/install_egg_info.py b/Lib/distutils/command/install_egg_info.py
index c2a7d64..0ddc736 100644
--- a/Lib/distutils/command/install_egg_info.py
+++ b/Lib/distutils/command/install_egg_info.py
@@ -21,10 +21,10 @@
 
     def finalize_options(self):
         self.set_undefined_options('install_lib',('install_dir','install_dir'))
-        basename = "%s-%s-py%s.egg-info" % (
+        basename = "%s-%s-py%d.%d.egg-info" % (
             to_filename(safe_name(self.distribution.get_name())),
             to_filename(safe_version(self.distribution.get_version())),
-            sys.version[:3]
+            *sys.version_info[:2]
         )
         self.target = os.path.join(self.install_dir, basename)
         self.outputs = [self.target]
diff --git a/Lib/distutils/sysconfig.py b/Lib/distutils/sysconfig.py
index 573724d..d203f8e 100644
--- a/Lib/distutils/sysconfig.py
+++ b/Lib/distutils/sysconfig.py
@@ -70,7 +70,7 @@
     leaving off the patchlevel.  Sample return values could be '1.5'
     or '2.2'.
     """
-    return sys.version[:3]
+    return '%d.%d' % sys.version_info[:2]
 
 
 def get_python_inc(plat_specific=0, prefix=None):
diff --git a/Lib/distutils/tests/test_build.py b/Lib/distutils/tests/test_build.py
index 3391f36..b020a5b 100644
--- a/Lib/distutils/tests/test_build.py
+++ b/Lib/distutils/tests/test_build.py
@@ -27,7 +27,7 @@
         # build_platlib is 'build/lib.platform-x.x[-pydebug]'
         # examples:
         #   build/lib.macosx-10.3-i386-2.7
-        plat_spec = '.%s-%s' % (cmd.plat_name, sys.version[0:3])
+        plat_spec = '.%s-%d.%d' % (cmd.plat_name, *sys.version_info[:2])
         if hasattr(sys, 'gettotalrefcount'):
             self.assertTrue(cmd.build_platlib.endswith('-pydebug'))
             plat_spec += '-pydebug'
@@ -42,7 +42,8 @@
         self.assertEqual(cmd.build_temp, wanted)
 
         # build_scripts is build/scripts-x.x
-        wanted = os.path.join(cmd.build_base, 'scripts-' +  sys.version[0:3])
+        wanted = os.path.join(cmd.build_base,
+                              'scripts-%d.%d' % sys.version_info[:2])
         self.assertEqual(cmd.build_scripts, wanted)
 
         # executable is os.path.normpath(sys.executable)
diff --git a/Lib/importlib/_bootstrap_external.py b/Lib/importlib/_bootstrap_external.py
index 71098f1..ddb2456 100644
--- a/Lib/importlib/_bootstrap_external.py
+++ b/Lib/importlib/_bootstrap_external.py
@@ -593,7 +593,7 @@
         else:
             registry_key = cls.REGISTRY_KEY
         key = registry_key.format(fullname=fullname,
-                                  sys_version=sys.version[:3])
+                                  sys_version='%d.%d' % sys.version_info[:2])
         try:
             with cls._open_registry(key) as hkey:
                 filepath = _winreg.QueryValue(hkey, '')
diff --git a/Lib/pydoc.py b/Lib/pydoc.py
index a73298d..5e5a8ae 100644
--- a/Lib/pydoc.py
+++ b/Lib/pydoc.py
@@ -1911,10 +1911,10 @@
 
     def intro(self):
         self.output.write('''
-Welcome to Python %s's help utility!
+Welcome to Python {0}'s help utility!
 
 If this is your first time using Python, you should definitely check out
-the tutorial on the Internet at http://docs.python.org/%s/tutorial/.
+the tutorial on the Internet at http://docs.python.org/{0}/tutorial/.
 
 Enter the name of any module, keyword, or topic to get help on writing
 Python programs and using Python modules.  To quit this help utility and
@@ -1924,7 +1924,7 @@
 "modules", "keywords", "symbols", or "topics".  Each module also comes
 with a one-line summary of what it does; to list the modules whose name
 or summary contain a given string such as "spam", type "modules spam".
-''' % tuple([sys.version[:3]]*2))
+'''.format('%d.%d' % sys.version_info[:2]))
 
     def list(self, items, columns=4, width=80):
         items = list(sorted(items))
diff --git a/Lib/site.py b/Lib/site.py
index 13ec8fa..56ba709 100644
--- a/Lib/site.py
+++ b/Lib/site.py
@@ -304,7 +304,7 @@
 
         if os.sep == '/':
             sitepackages.append(os.path.join(prefix, "lib",
-                                        "python" + sys.version[:3],
+                                        "python%d.%d" % sys.version_info[:2],
                                         "site-packages"))
         else:
             sitepackages.append(prefix)
@@ -317,7 +317,7 @@
             if framework:
                 sitepackages.append(
                         os.path.join("/Library", framework,
-                            sys.version[:3], "site-packages"))
+                            '%d.%d' % sys.version_info[:2], "site-packages"))
     return sitepackages
 
 def addsitepackages(known_paths, prefixes=None):
diff --git a/Lib/sysconfig.py b/Lib/sysconfig.py
index 9c34be0..f18b1bc 100644
--- a/Lib/sysconfig.py
+++ b/Lib/sysconfig.py
@@ -86,8 +86,8 @@
  # FIXME don't rely on sys.version here, its format is an implementation detail
  # of CPython, use sys.version_info or sys.hexversion
 _PY_VERSION = sys.version.split()[0]
-_PY_VERSION_SHORT = sys.version[:3]
-_PY_VERSION_SHORT_NO_DOT = _PY_VERSION[0] + _PY_VERSION[2]
+_PY_VERSION_SHORT = '%d.%d' % sys.version_info[:2]
+_PY_VERSION_SHORT_NO_DOT = '%d%d' % sys.version_info[:2]
 _PREFIX = os.path.normpath(sys.prefix)
 _BASE_PREFIX = os.path.normpath(sys.base_prefix)
 _EXEC_PREFIX = os.path.normpath(sys.exec_prefix)
@@ -386,7 +386,7 @@
         module.build_time_vars = vars
         sys.modules[name] = module
 
-    pybuilddir = 'build/lib.%s-%s' % (get_platform(), sys.version[:3])
+    pybuilddir = 'build/lib.%s-%s' % (get_platform(), _PY_VERSION_SHORT)
     if hasattr(sys, "gettotalrefcount"):
         pybuilddir += '-pydebug'
     os.makedirs(pybuilddir, exist_ok=True)
@@ -518,7 +518,7 @@
         _CONFIG_VARS['exec_prefix'] = _EXEC_PREFIX
         _CONFIG_VARS['py_version'] = _PY_VERSION
         _CONFIG_VARS['py_version_short'] = _PY_VERSION_SHORT
-        _CONFIG_VARS['py_version_nodot'] = _PY_VERSION[0] + _PY_VERSION[2]
+        _CONFIG_VARS['py_version_nodot'] = _PY_VERSION_SHORT_NO_DOT
         _CONFIG_VARS['installed_base'] = _BASE_PREFIX
         _CONFIG_VARS['base'] = _PREFIX
         _CONFIG_VARS['installed_platbase'] = _BASE_EXEC_PREFIX
diff --git a/Lib/test/test_importlib/test_windows.py b/Lib/test/test_importlib/test_windows.py
index c893bcf..005b685 100644
--- a/Lib/test/test_importlib/test_windows.py
+++ b/Lib/test/test_importlib/test_windows.py
@@ -40,7 +40,7 @@
     else:
         root = machinery.WindowsRegistryFinder.REGISTRY_KEY
     key = root.format(fullname=name,
-                      sys_version=sys.version[:3])
+                      sys_version='%d.%d' % sys.version_info[:2])
     try:
         with temp_module(name, "a = 1") as location:
             subkey = CreateKey(HKEY_CURRENT_USER, key)
diff --git a/Lib/test/test_site.py b/Lib/test/test_site.py
index 6615080..574e496 100644
--- a/Lib/test/test_site.py
+++ b/Lib/test/test_site.py
@@ -238,13 +238,14 @@
             self.assertEqual(len(dirs), 2)
             wanted = os.path.join('/Library',
                                   sysconfig.get_config_var("PYTHONFRAMEWORK"),
-                                  sys.version[:3],
+                                  '%d.%d' % sys.version_info[:2],
                                   'site-packages')
             self.assertEqual(dirs[1], wanted)
         elif os.sep == '/':
             # OS X non-framwework builds, Linux, FreeBSD, etc
             self.assertEqual(len(dirs), 1)
-            wanted = os.path.join('xoxo', 'lib', 'python' + sys.version[:3],
+            wanted = os.path.join('xoxo', 'lib',
+                                  'python%d.%d' % sys.version_info[:2],
                                   'site-packages')
             self.assertEqual(dirs[0], wanted)
         else:
diff --git a/Lib/test/test_venv.py b/Lib/test/test_venv.py
index 28b0f6c..f38f52d 100644
--- a/Lib/test/test_venv.py
+++ b/Lib/test/test_venv.py
@@ -51,7 +51,7 @@
             self.include = 'Include'
         else:
             self.bindir = 'bin'
-            self.lib = ('lib', 'python%s' % sys.version[:3])
+            self.lib = ('lib', 'python%d.%d' % sys.version_info[:2])
             self.include = 'include'
         if sys.platform == 'darwin' and '__PYVENV_LAUNCHER__' in os.environ:
             executable = os.environ['__PYVENV_LAUNCHER__']
diff --git a/Lib/urllib/request.py b/Lib/urllib/request.py
index 4c2b9fe..e3eed16 100644
--- a/Lib/urllib/request.py
+++ b/Lib/urllib/request.py
@@ -133,7 +133,7 @@
 ]
 
 # used in User-Agent header sent
-__version__ = sys.version[:3]
+__version__ = '%d.%d' % sys.version_info[:2]
 
 _opener = None
 def urlopen(url, data=None, timeout=socket._GLOBAL_DEFAULT_TIMEOUT,
diff --git a/Lib/xmlrpc/client.py b/Lib/xmlrpc/client.py
index bf42835..07a4f03 100644
--- a/Lib/xmlrpc/client.py
+++ b/Lib/xmlrpc/client.py
@@ -151,7 +151,7 @@
     return s.replace(">", ">",)
 
 # used in User-Agent header sent
-__version__ = sys.version[:3]
+__version__ = '%d.%d' % sys.version_info[:2]
 
 # xmlrpc integer limits
 MAXINT =  2**31-1