remove support for Python 2.7 and 3.5

.github/workflows/container_tests.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-22.04
     strategy:
       matrix:
-        python: [2.7, 3.7]
+        python: [3.7]
       fail-fast: false
     steps:
     - uses: actions/checkout@v3

.github/workflows/container_tests_apptainer.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-22.04
     strategy:
       matrix:
-        python: [2.7, 3.7]
+        python: [3.7]
         apptainer: [1.0.0, 1.1.7]
       fail-fast: false
     steps:

.github/workflows/eb_command.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-20.04
     strategy:
       matrix:
-        python: [2.7, 3.5, 3.6, 3.7, 3.8, 3.9, '3.10', '3.11']
+        python: [3.6, 3.7, 3.8, 3.9, '3.10', '3.11']
       fail-fast: false
     steps:
     - uses: actions/checkout@v3
@@ -91,7 +91,7 @@ jobs:
           pymajver=$(python -c 'import sys; print(sys.version_info[0])')
           pymajminver=$(python -c 'import sys; print(".".join(str(x) for x in sys.version_info[:2]))')
           # check patterns in verbose output
-          for pattern in "^>> Considering .python.\.\.\." "^>> .python. version: ${pymajminver}\.[0-9]\+, which matches Python ${pymajver} version requirement" "^>> 'python' is able to import 'easybuild.framework', so retaining it" "^>> Selected Python command: python \(.*/bin/python\)" "^This is EasyBuild 4\.[0-9.]\+"; do
+          for pattern in "^>> Considering .python3.\.\.\." "^>> .python3. version: ${pymajminver}\.[0-9]\+, which matches Python ${pymajver} version requirement" "^>> 'python3' is able to import 'easybuild.framework', so retaining it" "^>> Selected Python command: python3 \(.*/bin/python3\)" "^This is EasyBuild 4\.[0-9.]\+"; do
               echo "Looking for pattern \"${pattern}\" in eb_version.out..."
               grep "$pattern" eb_version.out
           done

.github/workflows/linting.yml

@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-20.04
     strategy:
       matrix:
-        python-version: [2.7, 3.5, 3.6, 3.7, 3.8, 3.9, '3.10', '3.11']
+        python-version: [3.6, 3.7, 3.8, 3.9, '3.10', '3.11']
 
     steps:
     - uses: actions/checkout@v3
@@ -30,10 +30,4 @@ jobs:
 
     - name: Run flake8 to verify PEP8-compliance of Python code
       run: |
-        # don't check py2vs3/py3.py when testing with Python 2, and vice versa
-        if [[ "${{ matrix.python-version }}" =~ "2." ]]; then
-            py_excl=py3
-        else
-            py_excl=py2
-        fi
-        flake8 --exclude ./easybuild/tools/py2vs3/${py_excl}.py
+        flake8

.github/workflows/unit_tests.yml

@@ -25,7 +25,7 @@ jobs:
     runs-on: ubuntu-20.04
     strategy:
       matrix:
-        python: [2.7, 3.6]
+        python: [3.6]
         modules_tool:
           # use variables defined by 'setup' job above, see also
           # https://docs.github.com/en/actions/reference/context-and-expression-syntax-for-github-actions#needs-context
@@ -46,9 +46,6 @@ jobs:
             module_syntax: Lua
         include:
           # Test different Python 3 versions with Lmod 8.x (with both Lua and Tcl module syntax)
-          - python: 3.5
-            modules_tool: ${{needs.setup.outputs.lmod8}}
-            module_syntax: Lua
           - python: 3.7
             modules_tool: ${{needs.setup.outputs.lmod8}}
             module_syntax: Lua
@@ -205,10 +202,6 @@ jobs:
           # create file owned by root but writable by anyone (used by test_copy_file)
           sudo touch /tmp/file_to_overwrite_for_easybuild_test_copy_file.txt
           sudo chmod o+w /tmp/file_to_overwrite_for_easybuild_test_copy_file.txt
-          # silence deprecation warning when using Python 2, since it breaks a bunch of tests
-          if [ "${{matrix.python}}" == '2.7' ]; then
-            export TEST_EASYBUILD_SILENCE_DEPRECATION_WARNINGS=python2
-          fi
           # run test suite
           python -O -m test.framework.suite 2>&1 | tee test_framework_suite.log
           # try and make sure output of running tests is clean (no printed messages/warnings)

easybuild/base/fancylogger.py

@@ -87,7 +87,6 @@
 import weakref
 
 from easybuild.tools import LooseVersion
-from easybuild.tools.py2vs3 import raise_with_traceback, string_type
 
 
 def _env_to_boolean(varname, default=False):
@@ -214,11 +213,11 @@ class MissingLevelName(KeyError):
 
 def getLevelInt(level_name):
     """Given a level name, return the int value"""
-    if not isinstance(level_name, string_type):
+    if not isinstance(level_name, str):
         raise TypeError('Provided name %s is not a string (type %s)' % (level_name, type(level_name)))
 
     level = logging.getLevelName(level_name)
-    if isinstance(level, string_type):
+    if isinstance(level, str):
         raise MissingLevelName('Unknown loglevel name %s' % level_name)
 
     return level
@@ -328,7 +327,7 @@ def raiseException(self, message, exception=None, catch=False):
             exception = self.RAISE_EXCEPTION_CLASS
 
         self.RAISE_EXCEPTION_LOG_METHOD(fullmessage)
-        raise_with_traceback(exception, message, tb)
+        raise exception(message).with_traceback(tb)
 
     # pylint: disable=unused-argument
     def deprecated(self, msg, cur_ver, max_ver, depth=2, exception=None, log_callback=None, *args, **kwargs):
@@ -588,7 +587,7 @@ def logToFile(filename, enable=True, filehandler=None, name=None, max_bytes=MAX_
             os.makedirs(directory)
         except Exception as ex:
             exc, detail, tb = sys.exc_info()
-            raise_with_traceback(exc, "Cannot create logdirectory %s: %s \n detail: %s" % (directory, ex, detail), tb)
+            raise exc("Cannot create logdirectory %s: %s \n detail: %s" % (directory, ex, detail)).with_traceback(tb)
 
     return _logToSomething(
         logging.handlers.RotatingFileHandler,
@@ -741,7 +740,7 @@ def setLogLevel(level):
     """
     Set a global log level for all FancyLoggers
     """
-    if isinstance(level, string_type):
+    if isinstance(level, str):
         level = getLevelInt(level)
     logger = getLogger(fname=False, clsname=False)
     logger.setLevel(level)

easybuild/base/frozendict.py

@@ -21,10 +21,10 @@
 It can be used as a drop-in replacement for dictionaries where immutability is desired.
 """
 import operator
+from collections.abc import Mapping
 from functools import reduce
 
 from easybuild.base import fancylogger
-from easybuild.tools.py2vs3 import Mapping
 
 
 # minor adjustments:

easybuild/base/generaloption.py

@@ -31,6 +31,7 @@
 * Jens Timmerman (Ghent University)
 """
 
+import configparser
 import copy
 import difflib
 import inspect
@@ -39,13 +40,15 @@
 import re
 import sys
 import textwrap
+from configparser import ConfigParser
 from functools import reduce
+from io import StringIO
 from optparse import Option, OptionGroup, OptionParser, OptionValueError, Values
 from optparse import SUPPRESS_HELP as nohelp  # supported in optparse of python v2.4
 
 from easybuild.base.fancylogger import getLogger, setroot, setLogLevel, getDetailsLogLevels
 from easybuild.base.optcomplete import autocomplete, CompleterOption
-from easybuild.tools.py2vs3 import StringIO, configparser, ConfigParser, string_type, subprocess_popen_text
+from easybuild.tools.run import subprocess_popen_text
 from easybuild.tools.utilities import mk_md_table, mk_rst_table, nub, shell_quote
 
 try:
@@ -133,7 +136,7 @@ def get_empty_add_flex(allvalues, self=None):
     empty = None
 
     if isinstance(allvalues, (list, tuple)):
-        if isinstance(allvalues[0], string_type):
+        if isinstance(allvalues[0], str):
             empty = ''
 
     if empty is None:
@@ -464,7 +467,7 @@ def is_value_a_commandline_option(self, opt, value, index=None):
         # --longopt=value, so no issues there either.
 
         # following checks assume that value is a string (not a store_or_None)
-        if not isinstance(value, string_type):
+        if not isinstance(value, str):
             return None
 
         cmdline_index = None
@@ -1191,7 +1194,7 @@ def add_group_parser(self, opt_dict, description, prefix=None, otherdefaults=Non
                         # choices
                         nameds['choices'] = ["%s" % x for x in extra_detail]  # force to strings
                         hlp += ' (choices: %s)' % ', '.join(nameds['choices'])
-                    elif isinstance(extra_detail, string_type) and len(extra_detail) == 1:
+                    elif isinstance(extra_detail, str) and len(extra_detail) == 1:
                         args.insert(0, "-%s" % extra_detail)
                     elif isinstance(extra_detail, (dict,)):
                         # extract any optcomplete completer hints

easybuild/base/optcomplete.py

@@ -107,7 +107,6 @@
 from optparse import OptionParser, Option
 from pprint import pformat
 
-from easybuild.tools.py2vs3 import string_type
 from easybuild.tools.utilities import shell_quote
 
 debugfn = None  # for debugging only
@@ -211,7 +210,7 @@ class FileCompleter(Completer):
     CALL_ARGS_OPTIONAL = ['prefix']
 
     def __init__(self, endings=None):
-        if isinstance(endings, string_type):
+        if isinstance(endings, str):
             endings = [endings]
         elif endings is None:
             endings = []
@@ -282,11 +281,11 @@ class RegexCompleter(Completer):
     def __init__(self, regexlist, always_dirs=True):
         self.always_dirs = always_dirs
 
-        if isinstance(regexlist, string_type):
+        if isinstance(regexlist, str):
             regexlist = [regexlist]
         self.regexlist = []
         for regex in regexlist:
-            if isinstance(regex, string_type):
+            if isinstance(regex, str):
                 regex = re.compile(regex)
             self.regexlist.append(regex)
 
@@ -546,15 +545,15 @@ def autocomplete(parser, arg_completer=None, opt_completer=None, subcmd_complete
     # File completion.
     if completer and (not prefix or not prefix.startswith('-')):
         # Call appropriate completer depending on type.
-        if isinstance(completer, (string_type, list, tuple)):
+        if isinstance(completer, (str, list, tuple)):
             completer = FileCompleter(completer)
         elif not isinstance(completer, (types.FunctionType, types.LambdaType, types.ClassType, types.ObjectType)):
             # TODO: what to do here?
             pass
 
         completions = completer(**completer_kwargs)
 
-    if isinstance(completions, string_type):
+    if isinstance(completions, str):
         # is a bash command, just run it
         if SHELL in (BASH,):  # TODO: zsh
             print(completions)

easybuild/base/rest.py

@@ -40,9 +40,10 @@
 import copy
 import json
 from functools import partial
+from urllib.parse import urlencode
+from urllib.request import HTTPSHandler, Request, build_opener
 
 from easybuild.base import fancylogger
-from easybuild.tools.py2vs3 import HTTPSHandler, Request, build_opener, json_loads, string_type, urlencode
 
 
 class Client(object):
@@ -180,7 +181,7 @@ def request(self, method, url, body, headers, content_type=None):
         else:
             body = conn.read()
             try:
-                pybody = json_loads(body)
+                pybody = json.loads(body)
             except ValueError:
                 pybody = body
         fancylogger.getLogger().debug('reponse len: %s ', len(pybody))
@@ -203,10 +204,8 @@ def get_connection(self, method, url, body, headers):
         else:
             sep = ''
 
-        # value passed to 'data' must be a 'bytes' value (not 'str') in Python 3.x, but a string value in Python 2
-        # hence, we encode the value obtained (if needed)
-        # this doesn't affect the value type in Python 2, and makes it a 'bytes' value in Python 3
-        if isinstance(body, string_type):
+        # value passed to 'data' must be a 'bytes' value (not 'str') hence, we encode the value obtained (if needed)
+        if isinstance(body, str):
             body = body.encode('utf-8')
 
         request = Request(self.url + sep + url, data=body)

easybuild/base/testing.py

@@ -39,16 +39,10 @@
 import re
 import sys
 from contextlib import contextmanager
-
-try:
-    from cStringIO import StringIO  # Python 2
-except ImportError:
-    from io import StringIO  # Python 3
+from io import StringIO
 
 from unittest import TestCase as OrigTestCase
 
-from easybuild.tools.py2vs3 import string_type
-
 
 def nicediff(txta, txtb, offset=5):
     """
@@ -85,7 +79,7 @@ class TestCase(OrigTestCase):
     def is_string(self, x):
         """test if the variable x is a string)"""
         try:
-            return isinstance(x, string_type)
+            return isinstance(x, str)
         except NameError:
             return isinstance(x, str)
 

easybuild/base/wrapper.py

@@ -6,7 +6,24 @@
 Original code by http://stackoverflow.com/users/416467/kindall from answer 4 of
 http://stackoverflow.com/questions/9057669/how-can-i-intercept-calls-to-pythons-magic-methods-in-new-style-classes
 """
-from easybuild.tools.py2vs3 import mk_wrapper_baseclass
+
+
+# based on six's 'with_metaclass' function
+# see also https://stackoverflow.com/questions/18513821/python-metaclass-understanding-the-with-metaclass
+def create_base_metaclass(base_class_name, metaclass, *bases):
+    """Create new class with specified metaclass based on specified base class(es)."""
+    return metaclass(base_class_name, bases, {})
+
+
+def mk_wrapper_baseclass(metaclass):
+
+    class WrapperBase(object, metaclass=metaclass):
+        """
+        Wrapper class that provides proxy access to an instance of some internal instance.
+        """
+        __wraps__ = None
+
+    return WrapperBase
 
 
 class WrapperMeta(type):