Code, doc and compatibility cleanups.

Author: Vlada Macek

.flake8

@@ -0,0 +1,7 @@
+[flake8]
+max-line-length = 120
+select = C,E,F,W,B,B9
+#ignore = E203, E501, W503
+ignore = W503
+exclude = build/*
+#migrations/*,tests_mixulo/*,mixulo/settings/*

CHANGELOG.md

@@ -3,9 +3,9 @@
 ## [dev]
 
 ## [0.9.0]
-- Added support for Django 4.0
-- Dropped support for Django <3.2
 - Dropped support for Python 2.x
+- Dropped support for Django <3.2
+- Added support for Django 4.0
 - Fixed CachedAuthenticationMiddleware to comply with Django system check framework
 
 ## [0.8.8]

README.rst

@@ -5,6 +5,8 @@ python-useful
 A collection of utilities of everyday use when writing
 Python 3.x code *or* Django 3.2+ projects.
 
+**Python 2.x support has been dropped.**
+
 Overview
 --------
 
@@ -27,11 +29,7 @@ Install either using pip::
 
     pip install useful
 
-Or using e-i::
-
-    easy_install useful
-
-Or from source::
+or from source::
 
     git clone https://github.com/tuttle/python-useful src/useful
     cd src/useful

setup.py

@@ -26,7 +26,6 @@
         "License :: OSI Approved :: BSD License",
         "Operating System :: OS Independent",
         "Programming Language :: Python",
-        "Programming Language :: Python :: 2",
         "Programming Language :: Python :: 3",
         "Topic :: Software Development :: Libraries",
     ],

tests/settings.py

@@ -1,10 +1,10 @@
-from django.conf.global_settings import *
+from django.conf.global_settings import *  # noqa
 
 
 DATABASES = {
     "default": {
         "ENGINE": "django.db.backends.sqlite3",
-        "NAME": "mem_db"
+        "NAME": "mem_db",
     }
 }
 
@@ -16,7 +16,7 @@
     "django.contrib.sessions",
     "django.contrib.sites",
     "useful.django",
-    "tests.testapp.apps.TestAppConfig"
+    "tests.testapp.apps.TestAppConfig",
 ]
 
 SECRET_KEY = 'justfortests'

tests/test_auth.py

@@ -1,8 +1,6 @@
-
 from django.contrib.auth import authenticate
 from django.contrib.auth.models import User
-from django.test import TestCase
-from django.test import override_settings
+from django.test import TestCase, override_settings
 
 
 @override_settings(AUTHENTICATION_BACKENDS=['useful.django.auth.EmailLoginModelBackend', ])

tests/test_cached_auth.py

@@ -1,4 +1,3 @@
-
 from django.core.management import call_command
 from django.test import TestCase
 from django.test import override_settings

tests/test_caching.py

@@ -1,4 +1,3 @@
-
 from django.test import TestCase
 from django.utils.crypto import get_random_string
 

tests/test_getters.py

@@ -1,4 +1,3 @@
-
 from django.contrib.auth.models import Group, User
 from django.test import TestCase
 

tests/test_logentry.py

@@ -1,4 +1,3 @@
-
 import json
 
 from django import VERSION

tests/test_templatetags.py

@@ -1,4 +1,3 @@
-
 from django.http import QueryDict
 from django.template.loader import render_to_string
 from django.test import TestCase

tests/test_urls.py

@@ -1,10 +1,7 @@
-
 from django.conf import settings
-from django.contrib.auth.models import Permission
-from django.contrib.auth.models import User
+from django.contrib.auth.models import Permission, User
 from django.contrib.contenttypes.models import ContentType
-from django.test import TestCase
-from django.test import override_settings
+from django.test import TestCase, override_settings
 from django.urls import reverse
 
 TEMPLATES = [

tests/test_views.py

@@ -1,4 +1,3 @@
-
 from django.test import TestCase
 from django.urls import reverse
 

tests/urls.py

@@ -1,4 +1,3 @@
-
 from django.urls import include
 from django.urls import path
 

useful/attrdict.py

@@ -1,4 +1,3 @@
-
 from collections import OrderedDict
 
 

useful/consistent_hash.py

@@ -1,4 +1,3 @@
-
 import bisect
 import hashlib
 

useful/daemontools.py

@@ -1,6 +1,6 @@
 import atexit
-import grp
 import logging.handlers
+import grp
 import os
 import pwd
 import signal
@@ -59,7 +59,7 @@ def sig_handler(signum, frame):
         if s not in (signal.SIGCHLD, signal.SIGURG, signal.SIGWINCH):
             try:
                 signal.signal(s, sig_handler)
-            except:
+            except:  # noqa
                 pass
 
 
@@ -88,7 +88,7 @@ def exit_function(pidfile_path_):
         try:
             logging.debug("Removing PID file %s." % pidfile_path_)
             os.unlink(pidfile_path_)
-        except:
+        except:  # noqa
             logging.error("Cannot remove PID file %s." % pidfile_path_)
 
     if os.path.exists(pidfile_path):

useful/django/auth.py

@@ -1,12 +1,10 @@
-
+from django.contrib.auth import get_user_model
 from django.contrib.auth.backends import ModelBackend
-from django.core.validators import validate_email, ValidationError
+from django.core.validators import ValidationError, validate_email
 from django.utils.crypto import get_random_string
-from django.contrib.auth import get_user_model
 
 from useful.django.getters import get_object_or_none
 
-
 UserModel = get_user_model()
 
 
@@ -56,7 +54,7 @@ def get_user_by_email(self, email):
 
         return user
 
-    def authenticate(self, request, username=None, password=None):
+    def authenticate(self, request, username=None, password=None, **kwargs):
         user = self.get_user_by_email(username)
         return user if user and user.check_password(password) else None
 
@@ -71,7 +69,7 @@ class UsernameOrEmailLoginModelBackend(EmailLoginModelBackend):
     """
     USERNAME_CASE_SENSITIVE = False
 
-    def authenticate(self, request, username=None, password=None):
+    def authenticate(self, request, username=None, password=None, **kwargs):
         if self.USERNAME_CASE_SENSITIVE:
             user = get_object_or_none(UserModel, username__exact=username)
         else:

useful/django/cached_auth.py

@@ -25,27 +25,28 @@
 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 """
 
+from django.apps import apps
 from django.conf import settings
-from django.contrib.auth import SESSION_KEY, get_user
+from django.contrib.auth import SESSION_KEY, get_user, get_user_model
 from django.contrib.auth.middleware import AuthenticationMiddleware
-from django.contrib.auth import get_user_model
 from django.core import cache  # Importing this way so debug_toolbar can patch it later.
-from django.db import models
 from django.db.models.signals import post_delete, post_save
 from django.utils.functional import SimpleLazyObject
 
-
 UserModel = get_user_model()
 
 CACHE_KEY = 'cached_auth_middleware_1.5:%s'
 
+# The profile model support have been deprecated in Django long time ago.
+# Nevertheless some projects might still be using it.
 try:
     app_label, model_name = settings.AUTH_PROFILE_MODULE.split('.')
-    profile_model = models.get_model(app_label, model_name)
+    profile_model = apps.get_model(app_label, model_name)
 except (ValueError, AttributeError):
     profile_model = None
 
 
+# noinspection PyUnusedLocal
 def invalidate_cache(sender, instance, **kwargs):
     if isinstance(instance, UserModel):
         key = CACHE_KEY % instance.id
@@ -80,6 +81,7 @@ def get_cached_user(request):
 
         request._cached_user = user
 
+    # noinspection PyProtectedMember
     return request._cached_user
 
 

useful/django/caching.py

@@ -1,11 +1,9 @@
-
-from functools import wraps
 import hashlib
+from functools import wraps
 
 from django.core import cache  # Importing this way so debug_toolbar can patch it later.
 from django.core.cache.backends.base import DEFAULT_TIMEOUT
 
-
 ALLOWED_CACHED_FUNCTION_ARG_TYPES = {type(None), int, float, bool, str, bytes}
 
 
@@ -41,16 +39,16 @@ def expensive(arg1, arg2, arg3):
         @cached_function(num_args_to_key=2)
 
     """
-    def cached_function_inner(func):
-        if func.__defaults__:
+    def cached_function_inner(fn):
+        if getattr(fn, '__defaults__'):
             raise RuntimeError("cached_function does not allow function to have default args "
                                "in order to keep the number of passed args fixed.")
 
-        if func.__name__ == '<lambda>':
+        if getattr(fn, '__name__') == '<lambda>':
             raise RuntimeError("cached_function can't work on anonymous funcs in order "
                                "to keep the name unique.")
 
-        @wraps(func)
+        @wraps(fn)
         def wrapper(*args):
             key_args = args if num_args_to_key is None else args[:num_args_to_key]
 
@@ -59,7 +57,7 @@ def wrapper(*args):
                 raise RuntimeError("cached_function received unallowed types of keyable args: %s"
                                    % ', '.join(map(str, unallowed_types)))
 
-            key_fmt = 'cached_function:%s.%s(%%s)' % (func.__module__, func.__name__)
+            key_fmt = 'cached_function:%s.%s(%%s)' % (fn.__module__, fn.__name__)
             key_args_repr = ','.join(map(repr, key_args))
             key = key_fmt % key_args_repr
 
@@ -68,13 +66,14 @@ def wrapper(*args):
                     key_args_bytestring = key_args_repr.encode('utf-8')
                 else:
                     key_args_bytestring = key_args_repr
+
                 key_args = hashlib.sha256(key_args_bytestring).hexdigest()
                 key = key_fmt % key_args + '-hashed'
 
             value = cache.cache.get(key)
 
             if value is None:
-                value = func(*args)
+                value = fn(*args)
 
                 cache.cache.set(key, value, timeout=timeout)
 

useful/django/can_url.py

@@ -1,11 +1,7 @@
-
 from functools import lru_cache
 
 from django.core.exceptions import PermissionDenied
-from django.urls import NoReverseMatch
-from django.urls import get_callable
-from django.urls import get_resolver
-from django.urls import URLResolver
+from django.urls import NoReverseMatch, URLResolver, get_callable, get_resolver
 from django.urls.base import get_urlconf
 
 

useful/django/concurrency.py

@@ -1,17 +1,13 @@
-
 import hashlib
 
-from django import VERSION
 from django import forms
 from django.contrib.auth.forms import UserChangeForm
 from django.forms.utils import ErrorList
+from django.utils.crypto import constant_time_compare, salted_hmac
 from django.utils.encoding import force_str, smart_str
 from django.utils.safestring import mark_safe
-from django.utils.crypto import salted_hmac, constant_time_compare
 from django.utils.translation import gettext_lazy as _
 
-
-
 CONCURRENCY_EDIT_MESSAGE = _(
     "<br><b>WARNING:</b> Your changes are almost LOST now and can't be saved.<br><em>But you still can copy the values "
     "out manually now.</em><br>Then you can <a href=''>RELOAD</a> and edit again."
@@ -45,14 +41,17 @@ def _clean_object_version(slf):
         raise RuntimeError(_("Found not matching primary key in object_version field."))
 
     if not slf.concurrency_problem:
+        # noinspection PyProtectedMember
         db_obj = slf._meta.model.objects.get(pk=pk)
         db_hash = _gen_object_hash(db_obj)
         if form_hash != db_hash:
+            # noinspection PyProtectedMember
             slf.concurrency_problem = \
                 _("In the mean time, someone <b>changed</b> this item in the database.") \
                 + ' ' + force_str(slf._CONCURRENCY_EDIT_MESSAGE)
 
     if slf.concurrency_problem:
+        # noinspection PyProtectedMember
         errors = slf._errors.setdefault(forms.forms.NON_FIELD_ERRORS, ErrorList())
         errors.append(mark_safe(slf.concurrency_problem))
 

useful/django/crypto.py

@@ -1,5 +1,3 @@
-
-from django import VERSION
 from django.utils.crypto import constant_time_compare, salted_hmac
 from django.utils.encoding import smart_str
 

useful/django/db.py

@@ -1,4 +1,3 @@
-
 from django.db import connection
 
 
@@ -7,6 +6,7 @@ def truncate_table(model_or_tablename, cascade=False, cursor=None):
         cursor = connection.cursor()
 
     if hasattr(model_or_tablename, '_meta'):
+        # noinspection PyProtectedMember
         tablename = model_or_tablename._meta.db_table
     else:
         tablename = model_or_tablename

useful/django/getters.py

@@ -1,4 +1,3 @@
-
 from collections import defaultdict
 
 from django.db import connection

useful/django/i18n.py

@@ -1,4 +1,3 @@
-
 import re
 
 from django.conf import settings

useful/django/logentry.py

@@ -1,5 +1,3 @@
-
-from django import VERSION
 from django.contrib import admin
 from django.contrib.admin.models import ADDITION, CHANGE, DELETION, LogEntry
 from django.contrib.admin.utils import construct_change_message

useful/django/readonly_admin.py

@@ -1,4 +1,3 @@
-
 from django.contrib import admin
 from django.core.exceptions import PermissionDenied
 

useful/django/remote_addr.py

@@ -1,4 +1,3 @@
-
 from django.conf import settings
 from django.core.exceptions import ImproperlyConfigured
 
@@ -24,7 +23,7 @@ class SetRemoteAddrMiddleware:
     """
     def __init__(self, get_response):
         self.get_response = get_response
-    
+
     def __call__(self, request):
         try:
             real_ip_varname = settings.REAL_IP_META_VARIABLE_NAME

useful/django/templatetags/freshstatic.py

@@ -1,4 +1,3 @@
-
 import os
 import posixpath
 import stat
@@ -8,7 +7,6 @@
 from django.conf import settings
 from django.contrib.staticfiles import finders, storage
 
-
 register = template.Library()
 
 STATIC_URL_CACHE = {}

useful/django/templatetags/useful.py

@@ -1,14 +1,12 @@
-
 import os
 import re
 import urllib.parse
 
-from django import VERSION, template
+from django import template
 from django.template.defaultfilters import stringfilter
+from django.utils.encoding import force_str
 from django.utils.html import urlize
 from django.utils.safestring import mark_safe
-from django.utils.encoding import force_str
-
 
 register = template.Library()
 

useful/django/urlpatterns.py

@@ -1,26 +1,15 @@
-
-from functools import wraps
-from functools import WRAPPER_ASSIGNMENTS
 import re
+from functools import wraps
 from urllib.parse import urlparse
 
 from django.conf import settings
-from django.urls import re_path
 from django.contrib.auth import REDIRECT_FIELD_NAME
 from django.core.exceptions import PermissionDenied
 from django.shortcuts import resolve_url
+from django.urls import re_path
 from django.utils.encoding import force_str
-from sys import version_info
-
 
-def available_attrs(fn):
-    """
-    Return the list of functools-wrappable attributes on a callable.
-    This is required as a workaround for http://bugs.python.org/issue3445
-    under Python 2.
-    TODO: still relevant in py3?
-    """
-    return WRAPPER_ASSIGNMENTS
+NOT_GIVEN = object()
 
 
 class UrlPatterns(list):
@@ -175,7 +164,7 @@ def __init__(self, login_url=None, raise_exception=False, redirect_field_name=No
         self.raise_exception = raise_exception
         self.redirect_field_name = redirect_field_name or REDIRECT_FIELD_NAME
 
-    def url(self, regex, kwargs=None, name=(), perms=None):
+    def url(self, regex, kwargs=None, name=NOT_GIVEN, perms=None):
         def decorator(view_func):
             if perms is None:
                 _wrapped = view_func
@@ -191,7 +180,7 @@ def __can_url(user):
                 _wrapped.can_url_perms_compiled = compiled_anded_perms
 
             # Assigning different name to avoid changing the nonlocal variable.
-            url_name = view_func.__name__ if name is () else name
+            url_name = view_func.__name__ if name is NOT_GIVEN else name
             self.append(re_path(regex, _wrapped, kwargs=kwargs, name=url_name))
 
             return _wrapped
@@ -223,7 +212,7 @@ def user_passes_test(self, test_func):
         Extended with passing the resolved aliased permissions to the view.
         """
         def decorator(view_func):
-            @wraps(view_func, assigned=available_attrs(view_func))
+            @wraps(view_func)
             def _wrapped_view(request, *args, **kwargs):
                 perm_aliases = test_func(request.user)
                 if perm_aliases:
@@ -242,8 +231,8 @@ def _wrapped_view(request, *args, **kwargs):
                 # use the path as the "next" url.
                 login_scheme, login_netloc = urlparse(resolved_login_url)[:2]
                 current_scheme, current_netloc = urlparse(path)[:2]
-                if ((not login_scheme or login_scheme == current_scheme) and
-                   (not login_netloc or login_netloc == current_netloc)):
+                if ((not login_scheme or login_scheme == current_scheme)
+                        and (not login_netloc or login_netloc == current_netloc)):
                     path = request.get_full_path()
                 from django.contrib.auth.views import redirect_to_login
                 return redirect_to_login(path, resolved_login_url,

useful/django/views.py

@@ -1,15 +1,14 @@
-
+import functools
 import os
 import time
-import functools
 
 import django
 from django import shortcuts
 from django.conf import settings
-from django.core.paginator import Paginator, EmptyPage, InvalidPage
-from django.urls import reverse
-from django.http.response import HttpResponse, HttpResponseBase, HttpResponseRedirect, HttpResponseBadRequest
+from django.core.paginator import EmptyPage, InvalidPage, Paginator
+from django.http.response import HttpResponse, HttpResponseBadRequest, HttpResponseBase, HttpResponseRedirect
 from django.template import RequestContext
+from django.urls import reverse
 
 from .crypto import SecretTokenGenerator
 
@@ -62,7 +61,7 @@ def page_decorator_inner_wrapper(request, *args, **kw):
                 data.update(response_dict)
 
             # The view can override the template to use.
-            template_name = data.get('template',  template)
+            template_name = data.get('template', template)
 
             # By adding the debug_template parameter we switch to possible debugging template:
             # payments/payments_info.html -> payments/payments_info_debug.html

useful/encoding.py

@@ -1,4 +1,3 @@
-
 import unicodedata
 
 

useful/filelock.py

@@ -1,11 +1,9 @@
-
 import errno
 import os
 import sys
 import time
 from functools import wraps
 
-
 # Based on http://www.evanfosmark.com/2009/01/cross-platform-file-locking-support-in-python/
 
 

useful/shortcuts.py

@@ -1,4 +1,5 @@
 
+# noinspection PyPep8Naming
 def first(predicate_or_None, iterable, default=None):
     """
     Returns the first item of iterable for which predicate(item) is true.
@@ -18,6 +19,7 @@ def int_or_0(value):
         return 0
 
 
+# noinspection PyPep8Naming
 def int_or_None(value):
     try:
         return int(value)

useful/transforms.py

@@ -1,4 +1,3 @@
-
 import itertools
 import operator
 from collections import defaultdict
@@ -82,7 +81,7 @@ def iter_compare_dicts(dict1, dict2, only_common_keys=False, comparison_op=opera
 
 def iter_ibatches(iterable, size):
     """
-    http://code.activestate.com/recipes/303279-getting-items-in-batches/
+    https://code.activestate.com/recipes/303279-getting-items-in-batches/
 
     Generates iterators of elements of fixed size from the source iterable. Does not create batch sequences in memory.
     The source iterable can be of an unknown arbitrary length, does not need to support anything else than iteration.