Merge pull request #11 from edx/ned/python3-compatibility

Make it work on Python 3

edx_lint/pylint/getattr_check.py

 """Check that getattr and setattr aren't being used with literal attribute names."""
 
+import six
+
 import astroid
 
 from pylint.checkers import BaseChecker, utils
@@ -49,7 +51,7 @@ class GetSetAttrLiteralChecker(BaseChecker):
 
         second = node.args[1]
         if isinstance(second, astroid.Const):
-            if isinstance(second.value, basestring):
+            if isinstance(second.value, six.string_types):
                 # The first argument is a constant string! Bad!
                 self.add_message(self.MESSAGE_ID, args=node.func.name, node=node)
 

edx_lint/pylint/i18n_check.py

+import six
+
 import astroid
 
 from pylint.checkers import BaseChecker, utils
@@ -51,7 +53,7 @@ class TranslationStringConstantsChecker(BaseChecker):
 
         first = node.args[0]
         if isinstance(first, astroid.Const):
-            if isinstance(first.value, basestring):
+            if isinstance(first.value, six.string_types):
                 # The first argument is a constant string! All is well!
                 return
 

edx_lint/tamper_evident.py

@@ -15,7 +15,7 @@ class TamperEvidentFile(object):
     def __init__(self, filename):
         self.filename = filename
 
-    def write(self, text, hashline="# {}"):
+    def write(self, text, hashline=b"# {}"):
         """
         Write `text` to the file.
 
@@ -25,16 +25,22 @@ class TamperEvidentFile(object):
         The last line is written with the `hashline` format string, which can
         be changed to accommodate different file syntaxes.
 
+        Arguments:
+            text (byte string): the contents of the file to write.
+
+            hashline (byte string): the format of the last line to append to
+                the file, with "{}" replaced with the hash.
+
         """
-        if not text.endswith("\n"):
-            text += "\n"
+        if not text.endswith(b"\n"):
+            text += b"\n"
 
         hash = hashlib.sha1(text).hexdigest()
 
-        with open(self.filename, "w") as f:
+        with open(self.filename, "wb") as f:
             f.write(text)
-            f.write(hashline.format(hash))
-            f.write("\n")
+            f.write(hashline.decode("ascii").format(hash).encode("ascii"))
+            f.write(b"\n")
 
     def validate(self):
         """
@@ -44,18 +50,18 @@ class TamperEvidentFile(object):
         with.
         """
 
-        with open(self.filename, "r") as f:
+        with open(self.filename, "rb") as f:
             text = f.read()
 
-        start_last_line = text.rfind("\n", 0, -1)
+        start_last_line = text.rfind(b"\n", 0, -1)
         if start_last_line == -1:
             return False
 
         original_text = text[:start_last_line+1]
         last_line = text[start_last_line+1:]
 
-        expected_hash = hashlib.sha1(original_text).hexdigest()
-        match = re.search(r"[0-9a-f]{40}", last_line)
+        expected_hash = hashlib.sha1(original_text).hexdigest().encode("ascii")
+        match = re.search(br"[0-9a-f]{40}", last_line)
         if not match:
             return False
         actual_hash = match.group(0)

test/input/func_i18n_computed_strings.py

@@ -2,7 +2,11 @@
 
 # pylint: disable=missing-docstring
 
-from string import lower as _, upper as gettext
+def _(text):
+    return text
+
+def gettext(text):
+    return text
 
 def welcome(name):
     _("Hello"+"There")

test/input/func_noerror_hello_world.py

-"""No-op file to see a test run."""
-
-print "Hello, world!"

test/input/func_noerror_ok_i18n.py

 """These are all good uses of _()"""
 
-from string import lower as _
+def _(text):
+    """A dummy _() to use."""
+    return text
 
 _("Hello")
 

test/input/func_noerror_range.py

 """Good uses of range."""
 
+import six
+
+if six.PY3:
+    def xrange(*args_unused):       # pylint: disable=unused-argument, redefined-builtin
+        """Just to keep PY3 happy."""
+
+
 i = 2
 
 range(10)

test/input/func_range.py

 """Bad uses of range()."""
 
+import six
+
+if six.PY3:
+    def xrange(*args_unused):       # pylint: disable=unused-argument, redefined-builtin
+        """Just to keep PY3 happy."""
+
 i = 12
 
 range(0, 10)

test/messages/func_i18n_computed_strings.txt

-E:  8:welcome: i18n function _() must be called with a literal string
-E:  9:welcome: i18n function _() must be called with a literal string
-E: 10:welcome: i18n function _() must be called with a literal string
-E: 14:welcome: i18n function gettext() must be called with a literal string
+E: 12:welcome: i18n function _() must be called with a literal string
+E: 13:welcome: i18n function _() must be called with a literal string
+E: 14:welcome: i18n function _() must be called with a literal string
+E: 18:welcome: i18n function gettext() must be called with a literal string

test/messages/func_range.txt

-C:  5: range() call could be single-argument
-C:  6: range() call could be single-argument
-C:  7: range() call could be single-argument
-C:  8: xrange() call could be single-argument
+C: 11: range() call could be single-argument
+C: 12: range() call could be single-argument
 C: 13: range() call could be single-argument
+C: 14: xrange() call could be single-argument
+C: 19: range() call could be single-argument

test/test_tamper_evident.py

@@ -23,60 +23,60 @@ class TamperEvidentFileTest(unittest.TestCase):
     def test_writing(self):
         # The contents are written, with a hash.
         # Different contents produce different hashes.
-        filename1 = self.write_tamper_evident("Hello!")
+        filename1 = self.write_tamper_evident(b"Hello!")
 
-        with open(filename1) as f:
+        with open(filename1, "rb") as f:
             self.assertEqual(
                 f.read(),
-                "Hello!\n# a8d191538209e335154750d2df575b9ddfb16fc7\n"
+                b"Hello!\n# a8d191538209e335154750d2df575b9ddfb16fc7\n"
             )
 
-        filename2 = self.write_tamper_evident("Hello?")
+        filename2 = self.write_tamper_evident(b"Hello?")
 
-        with open(filename2) as f:
+        with open(filename2, "rb") as f:
             self.assertEqual(
                 f.read(),
-                "Hello?\n# 4820175d44ef1a2c92e52bd1b3b7f05020d66e1c\n"
+                b"Hello?\n# 4820175d44ef1a2c92e52bd1b3b7f05020d66e1c\n"
             )
 
     def test_hashline_formatting(self):
-        filename1 = self.write_tamper_evident("Hello!", hashline="XXX {} YYY")
+        filename1 = self.write_tamper_evident(b"Hello!", hashline=b"XXX {} YYY")
 
-        with open(filename1) as f:
+        with open(filename1, "rb") as f:
             self.assertEqual(
                 f.read(),
-                "Hello!\nXXX a8d191538209e335154750d2df575b9ddfb16fc7 YYY\n"
+                b"Hello!\nXXX a8d191538209e335154750d2df575b9ddfb16fc7 YYY\n"
             )
 
     def test_validating_a_good_file(self):
-        filename = self.write_tamper_evident("Am I OK?")
+        filename = self.write_tamper_evident(b"Am I OK?")
         tef = TamperEvidentFile(filename)
         self.assertTrue(tef.validate())
 
     def test_appending_is_detected(self):
-        filename = self.write_tamper_evident("Am I OK?")
+        filename = self.write_tamper_evident(b"Am I OK?")
 
-        with open(filename, "a") as f:
-            f.write("tamper\n")
+        with open(filename, "ab") as f:
+            f.write(b"tamper\n")
 
         tef = TamperEvidentFile(filename)
         self.assertFalse(tef.validate())
 
     def test_editing_is_detected(self):
-        filename = self.write_tamper_evident("Line 1\nLine 2\nLine 3\n")
-        with open(filename, "r") as f:
+        filename = self.write_tamper_evident(b"Line 1\nLine 2\nLine 3\n")
+        with open(filename, "rb") as f:
             text = f.read()
-        with open(filename, "w") as f:
-            f.write("X")
+        with open(filename, "wb") as f:
+            f.write(b"X")
             f.write(text[1:])
         tef = TamperEvidentFile(filename)
         self.assertFalse(tef.validate())
 
     def test_oneline_file_is_detected(self):
-        filename = self.write_tamper_evident("Am I OK?")
+        filename = self.write_tamper_evident(b"Am I OK?")
 
-        with open(filename, "w") as f:
-            f.write("tamper")
+        with open(filename, "wb") as f:
+            f.write(b"tamper")
 
         tef = TamperEvidentFile(filename)
         self.assertFalse(tef.validate())