Revert "Support platform-specific requirements files"

This reverts commit 8cdb41cf1264e71fd2f479efa7decd38c1f91cfa.

https://www.python.org/dev/peps/pep-0426/#environment-markers is the
right approach for this, and as we haven't released master its safe to
back this out.

Change-Id: Ic7298fcbde54c6beda67c3c897efa75f1b60b78f

3 files changed, 5 insertions, 61 deletions

diff --git a/doc/source/index.rst b/doc/source/index.rst
index f36fc6f..918be40 100644
--- a/doc/source/index.rst
+++ b/doc/source/index.rst
@@ -107,21 +107,11 @@ You can also have a requirement file for each specific major version of
 Python. If you want to have a different package list for Python 3, just drop
 a requirements-py3.txt, and it will be used instead.
 
-It's also possible to select a requirement file specific for an OS. The format
-is requirements-{osname}.txt, where ``{osname}`` is the equivalent of
-``platform.system()``. The two approaches, Python version and OS version, can
-be combined.
-
 The requirement files are tried in that order (N being the Python major
-version number used to install the package and OS being the current
-platform's name in lowercase, retrieved with ``platform.system()``):
+version number used to install the package):
 
-* requirements-OS-pyN.txt
-* tools/pip-requires-OS-pyN
-* requirements-OS.txt
-* tools/pip-requires-OS
 * requirements-pyN.txt
-* tools/pip-requires-pyN
+* tools/pip-requires-py3
 * requirements.txt
 * tools/pip-requires
 
diff --git a/pbr/packaging.py b/pbr/packaging.py
index 8863651..e266d4f 100644
--- a/pbr/packaging.py
+++ b/pbr/packaging.py
@@ -23,10 +23,7 @@ from __future__ import unicode_literals
 from distutils.command import install as du_install
 from distutils import log
 import email
-import functools
-import itertools
 import os
-import platform
 import re
 import sys
 
@@ -55,26 +52,10 @@ def get_requirements_files():
     # Returns a list composed of:
     # - REQUIREMENTS_FILES with -py2 or -py3 in the name
     #   (e.g. requirements-py3.txt)
-    # - REQUIREMENTS_FILES with -{platform.system} in the name
-    #   (e.g. requirements-windows.txt)
-    # - REQUIREMENTS_FILES with both Python version and platform's
-    #   system in the name
-    #   (e.g. requirements-freebsd-py2.txt)
     # - REQUIREMENTS_FILES
-    pyversion = sys.version_info[0]
-    system = platform.system().lower()
-    parts = list(map(os.path.splitext, REQUIREMENTS_FILES))
-
-    version_cb = functools.partial("{1}-py{0}{2}".format, pyversion)
-    platform_cb = functools.partial("{1}-{0}{2}".format, system)
-    both_cb = functools.partial("{2}-{0}-py{1}{3}".format, system, pyversion)
-
-    return list(itertools.chain(
-        itertools.starmap(both_cb, parts),
-        itertools.starmap(platform_cb, parts),
-        itertools.starmap(version_cb, parts),
-        REQUIREMENTS_FILES,
-    ))
+    return (list(map(('-py' + str(sys.version_info[0])).join,
+                     map(os.path.splitext, REQUIREMENTS_FILES)))
+            + list(REQUIREMENTS_FILES))
 
 
 def append_text_list(config, key, text_list):
diff --git a/pbr/tests/test_packaging.py b/pbr/tests/test_packaging.py
index eac76b2..fccad45 100644
--- a/pbr/tests/test_packaging.py
+++ b/pbr/tests/test_packaging.py
@@ -40,7 +40,6 @@
 
 import os
 import re
-import sys
 import tempfile
 
 import fixtures
@@ -243,32 +242,6 @@ class TestNestedRequirements(base.BaseTestCase):
         self.assertEqual(result, ['pbr'])
 
 
-class TestGetRequirements(base.BaseTestCase):
-
-    def test_get_requirements_file(self):
-        platforms = ['Windows', 'Freebsd', 'Darwin', 'Linux']
-        version = sys.version_info[0]
-
-        with mock.patch('platform.system') as platform_system:
-            platform_system.side_effect = platforms
-
-            for platform in map(str.lower, platforms):
-                expected = [
-                    'requirements-{plat}-py{ver}.txt'.format(
-                        plat=platform, ver=version),
-                    'tools/pip-requires-{plat}-py{ver}'.format(
-                        plat=platform, ver=version),
-                    'requirements-{0}.txt'.format(platform),
-                    'tools/pip-requires-{0}'.format(platform),
-                    'requirements-py{0}.txt'.format(version),
-                    'tools/pip-requires-py{0}'.format(version),
-                    'requirements.txt',
-                    'tools/pip-requires',
-                ]
-                files = packaging.get_requirements_files()
-                self.assertEqual(expected, files)
-
-
 class TestVersions(base.BaseTestCase):
 
     scenarios = [