Use string.ascii_lowercase and string.ascii_uppercase only

"string.lowercase" and "string.uppercase" were removed in Python 3,
we can use only "string.ascii_lowercase" and "string.ascii_uppercase".

Change-Id: I97ddac01af7070129ad8baf5960c841482c346a2
Closes-Bug: #1405918

tests/hacking/README.rst

@@ -28,4 +28,5 @@ Rally Specific Commandments
  * [N333] - Ensure that ``urlparse`` is not used
  * [N334] - Ensure that ``itertools.imap`` is not used
  * [N335] - Ensure that ``xrange`` is not used
+ * [N336] - Ensure that ``string.lowercase`` and ``string.uppercase`` are not used
 * [N340] - Ensure that we are importing always ``from rally import objects``

tests/hacking/checks.py

@@ -51,6 +51,8 @@ re_StringIO_method = re.compile(r"StringIO\.StringIO\(")
 re_urlparse_method = re.compile(r"(^|[\s=])urlparse\.")
 re_itertools_imap_method = re.compile(r"(^|[\s=])itertools\.imap\(")
 re_xrange_method = re.compile(r"(^|[\s=])xrange\(")
+re_string_lower_upper_case_method = re.compile(
+    r"(^|[(,\s=])string\.(lower|upper)case([)\[,\s]|$)")
 
 
 def _parse_assert_mock_str(line):
@@ -306,6 +308,20 @@ def check_xrange_method(logical_line):
         yield (0, "N335: Use six.moves.range rather than xrange.")
 
 
+def check_string_lower_upper_case_method(logical_line):
+    """Check if string.lowercase and string.uppercase are properly called
+
+    In Python 3, string.lowercase and string.uppercase are gone.
+    The correct form is "string.ascii_lowercase" and "string.ascii_uppercase".
+
+    N336
+    """
+    res = re_string_lower_upper_case_method.search(logical_line)
+    if res:
+        yield (0, "N336: Use string.ascii_lowercase or string.ascii_uppercase "
+                  "rather than string.lowercase or string.uppercase.")
+
+
 def check_no_direct_rally_objects_import(logical_line, filename):
     """Check if rally.objects are properly imported.
 
@@ -339,4 +355,5 @@ def factory(register):
     register(check_urlparse_method)
     register(check_itertools_imap_method)
     register(check_xrange_method)
+    register(check_string_lower_upper_case_method)
     register(check_no_direct_rally_objects_import)

tests/unit/fakes.py

@@ -36,7 +36,7 @@ def generate_uuid():
     return str(uuid.uuid4())
 
 
-def generate_name(prefix="", length=12, choices=string.lowercase):
+def generate_name(prefix="", length=12, choices=string.ascii_lowercase):
     """Generate pseudo-random name.
 
     :param prefix: str, custom prefix for genertated name

tests/unit/test_hacking.py

@@ -163,6 +163,19 @@ class HackingTestCase(test.TestCase):
         self.assertEqual(len(list(checks.check_xrange_method(
             "six.moves.range()"))), 0)
 
+    def test_check_string_lower_upper_case_method(self):
+        self.assertEqual(len(list(checks.check_string_lower_upper_case_method(
+            "string.lowercase[:16]"))), 1)
+
+        self.assertEqual(len(list(checks.check_string_lower_upper_case_method(
+            "string.uppercase[:16]"))), 1)
+
+        self.assertEqual(len(list(checks.check_string_lower_upper_case_method(
+            "string.ascii_lowercase[:16]"))), 0)
+
+        self.assertEqual(len(list(checks.check_string_lower_upper_case_method(
+            "string.ascii_uppercase[:16]"))), 0)
+
     def test_assert_equal_none(self):
         self.assertEqual(len(list(checks.assert_equal_none(
             "self.assertEqual(A, None)"))), 1)