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"""
Settings and configuration for Django.
Read values from the module specified by the DJANGO_SETTINGS_MODULE environment
variable, and then from django.conf.global_settings; see the global_settings.py
for a list of all possible variables.
"""
import importlib
import os
import time
import traceback
import warnings
from pathlib import Path
import django
from django.conf import global_settings
from django.core.exceptions import ImproperlyConfigured
from django.utils.deprecation import (
RemovedInDjango30Warning, RemovedInDjango31Warning,
)
from django.utils.functional import LazyObject, empty
ENVIRONMENT_VARIABLE = "DJANGO_SETTINGS_MODULE"
DEFAULT_CONTENT_TYPE_DEPRECATED_MSG = 'The DEFAULT_CONTENT_TYPE setting is deprecated.'
FILE_CHARSET_DEPRECATED_MSG = (
'The FILE_CHARSET setting is deprecated. Starting with Django 3.1, all '
'files read from disk must be UTF-8 encoded.'
)
class LazySettings(LazyObject):
"""
A lazy proxy for either global Django settings or a custom settings object.
The user can manually configure settings prior to using them. Otherwise,
Django uses the settings module pointed to by DJANGO_SETTINGS_MODULE.
"""
def _setup(self, name=None):
"""
Load the settings module pointed to by the environment variable. This
is used the first time settings are needed, if the user hasn't
configured settings manually.
"""
settings_module = os.environ.get(ENVIRONMENT_VARIABLE)
if not settings_module:
desc = ("setting %s" % name) if name else "settings"
raise ImproperlyConfigured(
"Requested %s, but settings are not configured. "
"You must either define the environment variable %s "
"or call settings.configure() before accessing settings."
% (desc, ENVIRONMENT_VARIABLE))
self._wrapped = Settings(settings_module)
def __repr__(self):
# Hardcode the class name as otherwise it yields 'Settings'.
if self._wrapped is empty:
return '<LazySettings [Unevaluated]>'
return '<LazySettings "%(settings_module)s">' % {
'settings_module': self._wrapped.SETTINGS_MODULE,
}
def __getattr__(self, name):
"""Return the value of a setting and cache it in self.__dict__."""
if self._wrapped is empty:
self._setup(name)
val = getattr(self._wrapped, name)
self.__dict__[name] = val
return val
def __setattr__(self, name, value):
"""
Set the value of setting. Clear all cached values if _wrapped changes
(@override_settings does this) or clear single values when set.
"""
if name == '_wrapped':
self.__dict__.clear()
else:
self.__dict__.pop(name, None)
super().__setattr__(name, value)
def __delattr__(self, name):
"""Delete a setting and clear it from cache if needed."""
super().__delattr__(name)
self.__dict__.pop(name, None)
def configure(self, default_settings=global_settings, **options):
"""
Called to manually configure the settings. The 'default_settings'
parameter sets where to retrieve any unspecified values from (its
argument must support attribute access (__getattr__)).
"""
if self._wrapped is not empty:
raise RuntimeError('Settings already configured.')
holder = UserSettingsHolder(default_settings)
for name, value in options.items():
setattr(holder, name, value)
self._wrapped = holder
@property
def configured(self):
"""Return True if the settings have already been configured."""
return self._wrapped is not empty
@property
def DEFAULT_CONTENT_TYPE(self):
stack = traceback.extract_stack()
# Show a warning if the setting is used outside of Django.
# Stack index: -1 this line, -2 the caller.
filename, _line_number, _function_name, _text = stack[-2]
if not filename.startswith(os.path.dirname(django.__file__)):
warnings.warn(
DEFAULT_CONTENT_TYPE_DEPRECATED_MSG,
RemovedInDjango30Warning,
stacklevel=2,
)
return self.__getattr__('DEFAULT_CONTENT_TYPE')
@property
def FILE_CHARSET(self):
stack = traceback.extract_stack()
# Show a warning if the setting is used outside of Django.
# Stack index: -1 this line, -2 the caller.
filename, _line_number, _function_name, _text = stack[-2]
if not filename.startswith(os.path.dirname(django.__file__)):
warnings.warn(
FILE_CHARSET_DEPRECATED_MSG,
RemovedInDjango31Warning,
stacklevel=2,
)
return self.__getattr__('FILE_CHARSET')
class Settings:
def __init__(self, settings_module):
# update this dict from global settings (but only for ALL_CAPS settings)
for setting in dir(global_settings):
if setting.isupper():
setattr(self, setting, getattr(global_settings, setting))
# store the settings module in case someone later cares
self.SETTINGS_MODULE = settings_module
mod = importlib.import_module(self.SETTINGS_MODULE)
tuple_settings = (
"INSTALLED_APPS",
"TEMPLATE_DIRS",
"LOCALE_PATHS",
)
self._explicit_settings = set()
for setting in dir(mod):
if setting.isupper():
setting_value = getattr(mod, setting)
if (setting in tuple_settings and
not isinstance(setting_value, (list, tuple))):
raise ImproperlyConfigured("The %s setting must be a list or a tuple. " % setting)
setattr(self, setting, setting_value)
self._explicit_settings.add(setting)
if not self.SECRET_KEY:
raise ImproperlyConfigured("The SECRET_KEY setting must not be empty.")
if self.is_overridden('DEFAULT_CONTENT_TYPE'):
warnings.warn(DEFAULT_CONTENT_TYPE_DEPRECATED_MSG, RemovedInDjango30Warning)
if self.is_overridden('FILE_CHARSET'):
warnings.warn(FILE_CHARSET_DEPRECATED_MSG, RemovedInDjango31Warning)
if hasattr(time, 'tzset') and self.TIME_ZONE:
# When we can, attempt to validate the timezone. If we can't find
# this file, no check happens and it's harmless.
zoneinfo_root = Path('/usr/share/zoneinfo')
zone_info_file = zoneinfo_root.joinpath(*self.TIME_ZONE.split('/'))
if zoneinfo_root.exists() and not zone_info_file.exists():
raise ValueError("Incorrect timezone setting: %s" % self.TIME_ZONE)
# Move the time zone info into os.environ. See ticket #2315 for why
# we don't do this unconditionally (breaks Windows).
os.environ['TZ'] = self.TIME_ZONE
time.tzset()
def is_overridden(self, setting):
return setting in self._explicit_settings
def __repr__(self):
return '<%(cls)s "%(settings_module)s">' % {
'cls': self.__class__.__name__,
'settings_module': self.SETTINGS_MODULE,
}
class UserSettingsHolder:
"""Holder for user configured settings."""
# SETTINGS_MODULE doesn't make much sense in the manually configured
# (standalone) case.
SETTINGS_MODULE = None
def __init__(self, default_settings):
"""
Requests for configuration variables not in this class are satisfied
from the module specified in default_settings (if possible).
"""
self.__dict__['_deleted'] = set()
self.default_settings = default_settings
def __getattr__(self, name):
if name in self._deleted:
raise AttributeError
return getattr(self.default_settings, name)
def __setattr__(self, name, value):
self._deleted.discard(name)
if name == 'DEFAULT_CONTENT_TYPE':
warnings.warn(DEFAULT_CONTENT_TYPE_DEPRECATED_MSG, RemovedInDjango30Warning)
elif name == 'FILE_CHARSET':
warnings.warn(FILE_CHARSET_DEPRECATED_MSG, RemovedInDjango31Warning)
super().__setattr__(name, value)
def __delattr__(self, name):
self._deleted.add(name)
if hasattr(self, name):
super().__delattr__(name)
def __dir__(self):
return sorted(
s for s in [*self.__dict__, *dir(self.default_settings)]
if s not in self._deleted
)
def is_overridden(self, setting):
deleted = (setting in self._deleted)
set_locally = (setting in self.__dict__)
set_on_default = getattr(self.default_settings, 'is_overridden', lambda s: False)(setting)
return deleted or set_locally or set_on_default
def __repr__(self):
return '<%(cls)s>' % {
'cls': self.__class__.__name__,
}
settings = LazySettings()