Use six.moves.map instead of itertools.imap

In Python 3, module "itertools" doesn't contain "imap" object.
To support both Python 2 and Python 3, "six.moves.map"
should be used instead.

Change-Id: I5b82020d0721a91aa6d6090a42073a3285b80ff9
Closes-Bug: #1403434

tests/hacking/README.rst

@@ -26,4 +26,5 @@ Rally Specific Commandments
  * [N331] - Ensure that ``basestring`` is not used
  * [N332] - Ensure that ``StringIO.StringIO`` is not used
  * [N333] - Ensure that ``urlparse`` is not used
+ * [N334] - Ensure that ``itertools.imap`` is not used
 * [N340] - Ensure that we are importing always ``from rally import objects``

tests/hacking/checks.py

@@ -49,6 +49,7 @@ re_iteritems_method = re.compile(r"\.iteritems\(\)")
 re_basestring_method = re.compile(r"(^|[\s,(\[=])basestring([\s,)\]]|$)")
 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\(")
 
 
 def _parse_assert_mock_str(line):
@@ -280,6 +281,18 @@ def check_urlparse_method(logical_line):
         yield (0, "N333: Use six.moves.urllib.parse rather than urlparse.")
 
 
+def check_itertools_imap_method(logical_line):
+    """Check if itertools.imap is properly called for compatibility with Python 3
+
+    The correct form is six.moves.map instead of itertools.imap.
+
+    N334
+    """
+    res = re_itertools_imap_method.search(logical_line)
+    if res:
+        yield (0, "N334: Use six.moves.map rather than itertools.imap.")
+
+
 def check_no_direct_rally_objects_import(logical_line, filename):
     """Check if rally.objects are properly imported.
 
@@ -311,4 +324,5 @@ def factory(register):
     register(check_basestring_method)
     register(check_StringIO_method)
     register(check_urlparse_method)
+    register(check_itertools_imap_method)
     register(check_no_direct_rally_objects_import)

tests/unit/test_hacking.py

@@ -149,6 +149,13 @@ class HackingTestCase(test.TestCase):
         self.assertEqual(len(list(checks.check_urlparse_method(
             "six.moves.urllib.parse.urlparse(url)"))), 0)
 
+    def test_check_itertools_imap_method(self):
+        self.assertEqual(len(list(checks.check_itertools_imap_method(
+            "itertools.imap()"))), 1)
+
+        self.assertEqual(len(list(checks.check_itertools_imap_method(
+            "six.moves.map()"))), 0)
+
     def test_assert_equal_none(self):
         self.assertEqual(len(list(checks.assert_equal_none(
             "self.assertEqual(A, None)"))), 1)