Fix several issues related to compatibility between older and newer p…

…ython versions

.travis.yml

@@ -2,6 +2,10 @@ language: python
 
 jobs:
   include:
+    - os: linux
+      python: 2.7
+      env: TOXENV=py27
+
     - os: linux
       python: 3.5
       env: TOXENV=py35
@@ -22,6 +26,10 @@ jobs:
       python: 3.9
       env: TOXENV=py39
 
+    - os: linux
+      python: 3.10-dev
+      env: TOXENV=py310
+
 # Install the required packages not included in the standard distribution.
 install: pip install --no-cache-dir --upgrade tox
 

notebook_environments.py

@@ -8,9 +8,7 @@
 
 import argparse
 import base64
-import binascii
 import collections
-import contextlib
 import errno
 import glob
 import io
@@ -264,10 +262,8 @@ def _write_python_logos(path):
     for logo_name, logo_image in logos_spec.items():
         try:
             with io.open(os.path.join(path, logo_name), mode="wb") as stream_out:
-                # Skip this step when an unexpected error has occurred.
-                with contextlib.suppress(binascii.Error):
-                    # Create a new python logo on the current machine.
-                    stream_out.write(base64.b64decode(logo_image))
+                # Create a new python logo on the current machine.
+                stream_out.write(base64.b64decode(logo_image))
         except (IOError, OSError) as err:
             _logger.error("It's impossible to create python logos on the current machine.")
             _logger.debug("An unexpected error occurred at this program runtime:", exc_info=True)
@@ -369,8 +365,8 @@ def initialize_new_notebook_environment():
     try:
         from jupyter_core.paths import jupyter_path  # noqa
     except ImportError:
-        def jupyter_path(path):  # this function is to return a list
-            return [_get_data_path(path)]
+        def jupyter_path(subdirs):  # this function is to return a list
+            return [_get_data_path(subdirs)]
 
     # Find and remove all python kernels from the working notebook server.
     for path in jupyter_path("kernels"):

notebook_environments_test.py

@@ -14,12 +14,17 @@
 import subprocess
 import sys
 import unittest
-import unittest.mock as mock
 
+import six
 from pyfakefs.fake_filesystem_unittest import TestCase
 
 import notebook_environments
 
+try:
+    import unittest.mock as mock
+except ImportError:
+    import mock
+
 
 class SysMock(object):
 
@@ -85,8 +90,13 @@ def setUp(self):
                 json.dump(kernel_spec, stream_out)
 
     def tearDown(self):
-        # Remove all the fake python kernels after the each test case from the current machine.
-        self.fs.remove_object(self.data_path)
+        if os.path.exists(self.data_path):
+            # Remove all the fake python kernels after the each test case from the current machine.
+            self.fs.remove_object(self.data_path)
+
+    def _assertCountEqual(self, *args, **kwargs):
+        # An unordered sequence comparison asserting that the same elements.
+        return six.assertCountEqual(self, *args, **kwargs)
 
     @mock.patch.dict("notebook_environments.os.environ", {}, clear=True)
     def test_virtual_environment_active(self, sys_mock):
@@ -194,7 +204,7 @@ def test_get_kernel_name_error(self, logger_mock, basename_mock, sys_mock):
     def test_list_kernels_in(self, sys_mock):
         sys_mock.deactivate()
 
-        self.assertCountEqual(
+        self._assertCountEqual(  # for python2 and python3
             list(notebook_environments._list_kernels_in(self.data_path)),
             [
                 notebook_environments._kernel_info(os.path.basename(kernel_path), kernel_path)
@@ -242,7 +252,7 @@ def test_write_python_logos(self, logger_mock, sys_mock):
         self.assertTrue(os.path.isfile(os.path.join(self.data_path, "logo-32x32.png")))
         self.assertTrue(os.path.isfile(os.path.join(self.data_path, "logo-64x64.png")))
 
-        with mock.patch("notebook_environments.io.open", new=mock.mock_open()) as open_mock:
+        with mock.patch("notebook_environments.io.open") as open_mock:
             # Raise an operating system exception to test a function fault tolerance.
             open_mock.side_effect = OSError(errno.EPERM, "")
 
@@ -318,7 +328,7 @@ def test_write_kernel_specification(self, logger_mock, sys_mock):
             # Check the correctness of the current settings for the installed kernel system.
             self.assertEqual(json.load(stream_in), kernel_spec)
 
-        with mock.patch("notebook_environments.io.open", new=mock.mock_open()) as open_mock:
+        with mock.patch("notebook_environments.io.open") as open_mock:
             # Raise an operating system exception to test a function fault tolerance.
             open_mock.side_effect = OSError(errno.EPERM, "")
 
@@ -531,7 +541,7 @@ def test_remove_dead_kernels_error(self, logger_mock, list_kernels_in_mock, sys_
     def test_check_and_remove_broken_kernel(self, remove_dir_mock, sys_mock):
         sys_mock.deactivate()
 
-        with mock.patch("notebook_environments.io.open", new=mock.mock_open()) as open_mock:
+        with mock.patch("notebook_environments.io.open") as open_mock:
             # Raise an operating system exception to test a function fault tolerance.
             open_mock.side_effect = OSError(errno.EPERM, "")
 

setup.py

@@ -45,7 +45,7 @@
         "Source code": "https://github.com/vladpunko/notebook-environments",
     },
 
-    python_requires=">=3.0",  # this package is to work on python version 2.7 or later
+    python_requires=">=2.7",  # this package is to work on python version 2.7 or later
     platforms=["macOS", "POSIX"],
     py_modules=["notebook_environments"],
     classifiers=[
@@ -58,14 +58,15 @@
         "Operating System :: MacOS :: MacOS X",
         "Operating System :: POSIX",
 
-        # "Programming Language :: Python :: 2",
-        # "Programming Language :: Python :: 2.7",
+        "Programming Language :: Python :: 2",
+        "Programming Language :: Python :: 2.7",
         "Programming Language :: Python :: 3",
         "Programming Language :: Python :: 3.5",
         "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",
         "Programming Language :: Python :: 3.9",
+        "Programming Language :: Python :: 3.10",
 
         "Topic :: Software Development :: Libraries :: Python Modules",
         "Topic :: Utilities",

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py35, py36, py37, py38, py39
+envlist = py{27,35,36,37,38,39,310}
 
 # Ignore errors related to absence of some python interpreters on the current machine.
 skip_missing_interpreters = true
@@ -8,9 +8,12 @@ skip_missing_interpreters = true
 commands = pytest --cov --verbose notebook_environments_test.py
 deps =
     jupyter-core
-    pyfakefs<4.5.0  # mock the python file system modules
+    mock
     pytest
     pytest-cov
+    six
+    py{27,35}: pyfakefs<4.5.0 # mock the python file system modules for some previous interpreter versions
+    py{36,37,38,39,310}: pyfakefs
 
 [testenv:lint]
 commands = python -m pre_commit run --all-files --config .githooks.yml