Remove use of six

pylintrc

@@ -287,7 +287,7 @@ ignore-on-opaque-inference=yes
 # List of class names for which member attributes should not be checked (useful
 # for classes with dynamically set attributes). This supports the use of
 # qualified names.
-ignored-classes=optparse.Values,thread._local,_thread._local, six.moves
+ignored-classes=optparse.Values,thread._local,_thread._local
 
 # List of module names for which member attributes should not be checked
 # (useful for modules/projects where namespaces are manipulated during runtime
@@ -334,7 +334,7 @@ init-import=no
 
 # List of qualified module names which can have objects that can redefine
 # builtins.
-redefining-builtins-modules=six.moves,future.builtins
+redefining-builtins-modules=future.builtins
 
 
 [CLASSES]

requirements-pinned.txt

@@ -7,5 +7,4 @@ pycparser==2.20           # via cffi
 pynacl==1.4.0             # via securesystemslib
 requests==2.25.1
 securesystemslib[crypto,pynacl]==0.20.0
-six==1.15.0
 urllib3==1.26.4           # via requests

requirements.txt

@@ -43,4 +43,3 @@
 #
 securesystemslib[crypto, pynacl]
 requests
-six

setup.py

@@ -113,8 +113,7 @@
   python_requires="~=3.6",
   install_requires = [
     'requests>=2.19.1',
-    'securesystemslib>=0.20.0',
-    'six>=1.11.0'
+    'securesystemslib>=0.20.0'
   ],
   packages = find_packages(exclude=['tests']),
   scripts = [

tests/simple_https_server.py

@@ -40,7 +40,7 @@
 import sys
 import ssl
 import os
-import six
+import http.server
 
 keyfile = os.path.join('ssl_certs', 'ssl_cert.key')
 certfile = os.path.join('ssl_certs', 'ssl_cert.crt')
@@ -49,8 +49,8 @@
 if len(sys.argv) > 1 and os.path.exists(sys.argv[1]):
     certfile = sys.argv[1]
 
-httpd = six.moves.BaseHTTPServer.HTTPServer(('localhost', 0),
-    six.moves.SimpleHTTPServer.SimpleHTTPRequestHandler)
+httpd = http.server.HTTPServer(('localhost', 0),
+   http.server.SimpleHTTPRequestHandler)
 
 httpd.socket = ssl.wrap_socket(
     httpd.socket, keyfile=keyfile, certfile=certfile, server_side=True)

tests/simple_server.py

@@ -35,9 +35,8 @@
 
 import sys
 import random
-
-import six
-from six.moves.SimpleHTTPServer import SimpleHTTPRequestHandler
+import socketserver
+from http.server import SimpleHTTPRequestHandler
 
 
 class QuietHTTPRequestHandler(SimpleHTTPRequestHandler):
@@ -64,9 +63,9 @@ def log_request(self, code='-', size='-'):
 
 # Allow re-use so you can re-run tests as often as you want even if the
 # tests re-use ports. Otherwise TCP TIME-WAIT prevents reuse for ~1 minute
-six.moves.socketserver.TCPServer.allow_reuse_address = True
+socketserver.TCPServer.allow_reuse_address = True
 
-httpd = six.moves.socketserver.TCPServer(('localhost', 0), handler)
+httpd = socketserver.TCPServer(('localhost', 0), handler)
 port_message = 'bind succeeded, server port is: ' \
     + str(httpd.server_address[1])
 print(port_message)

tests/slow_retrieval_server.py

@@ -32,13 +32,12 @@
 import os
 import sys
 import time
-
-import six
+import http.server
 
 
 
 # HTTP request handler.
-class Handler(six.moves.BaseHTTPServer.BaseHTTPRequestHandler):
+class Handler(http.server.BaseHTTPRequestHandler):
 
   # Overwrite do_GET.
   def do_GET(self):
@@ -66,7 +65,7 @@ def do_GET(self):
 if __name__ == '__main__':
   server_address = ('localhost', 0)
 
-  httpd = six.moves.BaseHTTPServer.HTTPServer(server_address, Handler)
+  httpd = http.server.HTTPServer(server_address, Handler)
   port_message = 'bind succeeded, server port is: ' \
       + str(httpd.server_address[1])
   print(port_message)

tests/test_arbitrary_package_attack.py

@@ -43,6 +43,7 @@
 import logging
 import unittest
 import sys
+from urllib import request
 
 import tuf
 import tuf.formats
@@ -55,7 +56,6 @@
 from tests import utils
 
 import securesystemslib
-import six
 
 logger = logging.getLogger(__name__)
 
@@ -174,7 +174,7 @@ def test_without_tuf(self):
     url_file = os.path.join(url_prefix, 'targets', 'file1.txt')
 
     # On Windows, the URL portion should not contain back slashes.
-    six.moves.urllib.request.urlretrieve(url_file.replace('\\', '/'), client_target_path)
+    request.urlretrieve(url_file.replace('\\', '/'), client_target_path)
 
     self.assertTrue(os.path.exists(client_target_path))
     length, hashes = securesystemslib.util.get_file_details(client_target_path)
@@ -188,7 +188,7 @@ def test_without_tuf(self):
     malicious_fileinfo = tuf.formats.make_targets_fileinfo(length, hashes)
 
     # On Windows, the URL portion should not contain back slashes.
-    six.moves.urllib.request.urlretrieve(url_file.replace('\\', '/'), client_target_path)
+    request.urlretrieve(url_file.replace('\\', '/'), client_target_path)
 
     length, hashes = securesystemslib.util.get_file_details(client_target_path)
     download_fileinfo = tuf.formats.make_targets_fileinfo(length, hashes)

tests/test_endless_data_attack.py

@@ -46,6 +46,7 @@
 import logging
 import unittest
 import sys
+from urllib import request
 
 import tuf
 import tuf.formats
@@ -57,7 +58,6 @@
 from tests import utils
 
 import securesystemslib
-import six
 
 logger = logging.getLogger(__name__)
 
@@ -176,7 +176,7 @@ def test_without_tuf(self):
     url_file = os.path.join(url_prefix, 'targets', 'file1.txt')
 
     # On Windows, the URL portion should not contain backslashes.
-    six.moves.urllib.request.urlretrieve(url_file.replace('\\', '/'), client_target_path)
+    request.urlretrieve(url_file.replace('\\', '/'), client_target_path)
 
     self.assertTrue(os.path.exists(client_target_path))
     length, hashes = securesystemslib.util.get_file_details(client_target_path)
@@ -194,7 +194,7 @@ def test_without_tuf(self):
     self.assertTrue(large_length > length)
 
     # On Windows, the URL portion should not contain backslashes.
-    six.moves.urllib.request.urlretrieve(url_file.replace('\\', '/'), client_target_path)
+    request.urlretrieve(url_file.replace('\\', '/'), client_target_path)
 
     length, hashes = securesystemslib.util.get_file_details(client_target_path)
     download_fileinfo = tuf.formats.make_targets_fileinfo(length, hashes)
@@ -269,7 +269,7 @@ def test_with_tuf(self):
       self.repository_updater.refresh()
 
     except tuf.exceptions.NoWorkingMirrorError as exception:
-      for mirror_url, mirror_error in six.iteritems(exception.mirror_errors):
+      for mirror_url, mirror_error in exception.mirror_errors.items():
         self.assertTrue(isinstance(mirror_error, securesystemslib.exceptions.Error))
 
     else:

tests/test_extraneous_dependencies_attack.py

@@ -60,7 +60,6 @@
 from tests import utils
 
 import securesystemslib
-import six
 
 logger = logging.getLogger(__name__)
 
@@ -206,7 +205,7 @@ def test_with_tuf(self):
     # Verify that the specific 'tuf.exceptions.ForbiddenTargetError' exception is raised
     # by each mirror.
     except tuf.exceptions.NoWorkingMirrorError as exception:
-      for mirror_url, mirror_error in six.iteritems(exception.mirror_errors):
+      for mirror_url, mirror_error in exception.mirror_errors.items():
         url_prefix = self.repository_mirrors['mirror1']['url_prefix']
         url_file = os.path.join(url_prefix, 'metadata', 'role1.json')
 

tests/test_formats.py

@@ -40,7 +40,6 @@
 
 import securesystemslib
 import securesystemslib.util
-import six
 
 
 class TestFormats(unittest.TestCase):
@@ -287,15 +286,15 @@ def test_schemas(self):
 
     # Iterate 'valid_schemas', ensuring each 'valid_schema' correctly matches
     # its respective 'schema_type'.
-    for schema_name, (schema_type, valid_schema) in six.iteritems(valid_schemas):
+    for schema_name, (schema_type, valid_schema) in valid_schemas.items():
       if not schema_type.matches(valid_schema):
         print('bad schema: ' + repr(valid_schema))
       self.assertEqual(True, schema_type.matches(valid_schema))
 
     # Test conditions for invalid schemas.
     # Set the 'valid_schema' of 'valid_schemas' to an invalid
     # value and test that it does not match 'schema_type'.
-    for schema_name, (schema_type, valid_schema) in six.iteritems(valid_schemas):
+    for schema_name, (schema_type, valid_schema) in valid_schemas.items():
       invalid_schema = 0xBAD
       if isinstance(schema_type, securesystemslib.schema.Integer):
         invalid_schema = 'BAD'
@@ -779,7 +778,7 @@ def test_format_base64(self):
     # Test conditions for valid arguments.
     data = 'updateframework'.encode('utf-8')
     self.assertEqual('dXBkYXRlZnJhbWV3b3Jr', tuf.formats.format_base64(data))
-    self.assertTrue(isinstance(tuf.formats.format_base64(data), six.string_types))
+    self.assertTrue(isinstance(tuf.formats.format_base64(data), str))
 
     # Test conditions for invalid arguments.
     self.assertRaises(securesystemslib.exceptions.FormatError, tuf.formats.format_base64, 123)
@@ -791,7 +790,7 @@ def test_parse_base64(self):
     # Test conditions for valid arguments.
     base64 = 'dXBkYXRlZnJhbWV3b3Jr'
     self.assertEqual(b'updateframework', tuf.formats.parse_base64(base64))
-    self.assertTrue(isinstance(tuf.formats.parse_base64(base64), six.binary_type))
+    self.assertTrue(isinstance(tuf.formats.parse_base64(base64), bytes))
 
     # Test conditions for invalid arguments.
     self.assertRaises(securesystemslib.exceptions.FormatError, tuf.formats.parse_base64, 123)

tests/test_indefinite_freeze_attack.py

@@ -53,6 +53,7 @@
 import logging
 import unittest
 import sys
+from urllib import request
 
 if sys.version_info >= (3, 3):
   import unittest.mock as mock
@@ -71,7 +72,6 @@
 from tests import utils
 
 import securesystemslib
-import six
 
 # The repository tool is imported and logs console messages by default.  Disable
 # console log messages generated by this unit test.
@@ -223,7 +223,7 @@ def test_without_tuf(self):
     url_prefix = self.repository_mirrors['mirror1']['url_prefix']
     url_file = os.path.join(url_prefix, 'metadata', 'timestamp.json')
 
-    six.moves.urllib.request.urlretrieve(url_file.replace('\\', '/'), client_timestamp_path)
+    request.urlretrieve(url_file.replace('\\', '/'), client_timestamp_path)
 
     length, hashes = securesystemslib.util.get_file_details(client_timestamp_path)
     download_fileinfo = tuf.formats.make_targets_fileinfo(length, hashes)
@@ -367,7 +367,7 @@ def test_with_tuf(self):
 
       except tuf.exceptions.NoWorkingMirrorError as e:
         # Make sure the contained error is ExpiredMetadataError
-        for mirror_url, mirror_error in six.iteritems(e.mirror_errors):
+        for mirror_url, mirror_error in e.mirror_errors.items():
           self.assertTrue(isinstance(mirror_error, tuf.exceptions.ExpiredMetadataError))
 
       else:
@@ -427,7 +427,7 @@ def test_with_tuf(self):
 
       except tuf.exceptions.NoWorkingMirrorError as e:
         # Make sure the contained error is ExpiredMetadataError
-        for mirror_url, mirror_error in six.iteritems(e.mirror_errors):
+        for mirror_url, mirror_error in e.mirror_errors.items():
           self.assertTrue(isinstance(mirror_error, tuf.exceptions.ExpiredMetadataError))
           self.assertTrue(mirror_url.endswith('snapshot.json'))
 

tests/test_key_revocation_integration.py

@@ -55,7 +55,6 @@
 from tests import utils
 
 import securesystemslib
-import six
 
 logger = logging.getLogger(__name__)
 repo_tool.disable_console_log_messages()

tests/test_log.py

@@ -25,6 +25,7 @@
 import os
 import shutil
 import sys
+import importlib
 
 import tuf
 import tuf.log
@@ -35,7 +36,6 @@
 
 from tests import utils
 
-from six.moves import reload_module
 
 # We explicitly create a logger which is a child of the tuf hierarchy,
 # instead of using the standard getLogger(__name__) pattern, because the
@@ -96,7 +96,7 @@ def test_set_filehandler_log_level(self):
     # Test that the log level of the file handler cannot be set because
     # file logging is disabled (via tuf.settings.ENABLE_FILE_LOGGING).
     tuf.settings.ENABLE_FILE_LOGGING = False
-    reload_module(tuf.log)
+    importlib.reload(tuf.log)
 
     # Test for improperly formatted argument.
     self.assertRaises(securesystemslib.exceptions.FormatError, tuf.log.set_filehandler_log_level, '123')

tests/test_mix_and_match_attack.py

@@ -55,7 +55,6 @@
 
 from tests import utils
 
-import six
 
 # The repository tool is imported and logs console messages by default.
 # Disable console log messages generated by this unit test.
@@ -227,7 +226,7 @@ def test_with_tuf(self):
     # 'tuf.exceptions.BadVersionNumberError' exception is raised by
     # each mirror.
     except tuf.exceptions.NoWorkingMirrorError as exception:
-      for mirror_url, mirror_error in six.iteritems(exception.mirror_errors):
+      for mirror_url, mirror_error in exception.mirror_errors.items():
         url_prefix = self.repository_mirrors['mirror1']['url_prefix']
         url_file = os.path.join(url_prefix, 'metadata', 'role1.json')
 

tests/test_multiple_repositories_integration.py

@@ -47,7 +47,6 @@
 
 from tests import utils
 
-import six
 import securesystemslib
 
 logger = logging.getLogger(__name__)
@@ -271,7 +270,7 @@ def test_repository_tool(self):
     multi_repo_updater = updater.MultiRepoUpdater(self.map_file)
     valid_targetinfo = multi_repo_updater.get_valid_targetinfo('file3.txt')
 
-    for my_updater, my_targetinfo in six.iteritems(valid_targetinfo):
+    for my_updater, my_targetinfo in valid_targetinfo.items():
       my_updater.download_target(my_targetinfo, self.temporary_directory)
       self.assertTrue(os.path.exists(os.path.join(self.temporary_directory, 'file3.txt')))
 

tests/test_replay_attack.py

@@ -45,6 +45,7 @@
 import logging
 import unittest
 import sys
+from urllib import request
 
 import tuf.formats
 import tuf.log
@@ -55,7 +56,7 @@
 from tests import utils
 
 import securesystemslib
-import six
+
 
 # The repository tool is imported and logs console messages by default.
 # Disable console log messages generated by this unit test.
@@ -220,7 +221,7 @@ def test_without_tuf(self):
         self.repository_name, 'metadata', 'current', 'timestamp.json')
 
     # On Windows, the URL portion should not contain back slashes.
-    six.moves.urllib.request.urlretrieve(url_file.replace('\\', '/'), client_timestamp_path)
+    request.urlretrieve(url_file.replace('\\', '/'), client_timestamp_path)
 
     length, hashes = securesystemslib.util.get_file_details(client_timestamp_path)
     download_fileinfo = tuf.formats.make_targets_fileinfo(length, hashes)
@@ -233,7 +234,7 @@ def test_without_tuf(self):
     shutil.move(backup_timestamp, timestamp_path)
 
     # On Windows, the URL portion should not contain back slashes.
-    six.moves.urllib.request.urlretrieve(url_file.replace('\\', '/'), client_timestamp_path)
+    request.urlretrieve(url_file.replace('\\', '/'), client_timestamp_path)
 
     length, hashes = securesystemslib.util.get_file_details(client_timestamp_path)
     download_fileinfo = tuf.formats.make_targets_fileinfo(length, hashes)
@@ -312,7 +313,7 @@ def test_with_tuf(self):
     # Verify that the specific 'tuf.exceptions.ReplayedMetadataError' is raised by each
     # mirror.
     except tuf.exceptions.NoWorkingMirrorError as exception:
-      for mirror_url, mirror_error in six.iteritems(exception.mirror_errors):
+      for mirror_url, mirror_error in exception.mirror_errors.items():
         url_prefix = self.repository_mirrors['mirror1']['url_prefix']
         url_file = os.path.join(url_prefix, 'metadata', 'timestamp.json')