在过去的几天里，我一直在尝试在django中使用环境变量，但这似乎是不可能的。我制作了我的. env文件，并把它放在我的项目目录中，所有的变量。当我运行服务器时，它说我的密钥没有定义，即使我正在加载我的环境变量。我不知道我在这个项目中做错了什么，因为这种方法在我做的另一个项目中工作得很好。
如果有人能找到错误，我真的会非常感激。

• • 设置. py**

"""
Django settings for server project.

Generated by 'django-admin startproject' using Django 3.1.6.

For more information on this file, see
https://docs.djangoproject.com/en/3.1/topics/settings/

For the full list of settings and their values, see
https://docs.djangoproject.com/en/3.1/ref/settings/
"""

import django_heroku
from pathlib import Path
import os
import dj_database_url
import dotenv

# Build paths inside the project like this: BASE_DIR / 'subdir'.
BASE_DIR = Path(__file__).resolve().parent.parent

dotenv_file = os.path.join(BASE_DIR, "env")
if os.path.isfile(dotenv_file):
    dotenv.load_dotenv(dotenv_file)

# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/3.1/howto/deployment/checklist/

# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = os.environ.get("SECRET_KEY")

# SECURITY WARNING: don't run with debug turned on in production!
DEBUG = True

ALLOWED_HOSTS = ['postsingle.herokuapp.com', '127.0.0.1']

# Application definition

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'rest_framework',
    'posts',
    'corsheaders',
    'knox',
    'accounts',
]

REST_FRAMEWORK = {
    'DEFAULT_AUTHENTICATION_CLASSES':
    ('knox.auth.TokenAuthentication',)
}

MIDDLEWARE = [
    'corsheaders.middleware.CorsMiddleware',
    'django.middleware.security.SecurityMiddleware',
    'whitenoise.middleware.WhiteNoiseMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

ROOT_URLCONF = 'server.urls'

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [os.path.join(BASE_DIR, 'templates')],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

WSGI_APPLICATION = 'server.wsgi.application'

# Database
# https://docs.djangoproject.com/en/3.1/ref/settings/#databases

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql',
        'NAME': os.environ.get("DATABASE_NAME"),
        'USER': os.environ.get("DATABASE_USER"),
        'PASSWORD': os.environ.get("DATABASE_PASSWORD"),
        'HOST': os.environ.get("DATABASE_HOST"),
        'PORT': os.environ.get("DATABASE_PORT"),
    }
}

db_from_env = dj_database_url.config(conn_max_age=600)
DATABASES['default'].update(db_from_env)

# Password validation
# https://docs.djangoproject.com/en/3.1/ref/settings/#auth-password-validators

AUTH_PASSWORD_VALIDATORS = [
    {
        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
    },
]

# Internationalization
# https://docs.djangoproject.com/en/3.1/topics/i18n/

LANGUAGE_CODE = 'en-us'

TIME_ZONE = 'UTC'

USE_I18N = True

USE_L10N = True

USE_TZ = True

# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/3.1/howto/static-files/

STATIC_URL = '/static/'

STATIC_ROOT = os.path.join(BASE_DIR, 'staticfiles')

STATICFILES_DIRS = [
    os.path.join(BASE_DIR, 'static')
]

STATICFILES_STORAGE = 'whitenoise.storage.CompressedManifestStaticFilesStorage'

CORS_ORIGIN_WHITELIST = [
    'http://localhost:3000',
    'https://postsingle.herokuapp.com'
]

django_heroku.settings(locals())

• • EDIT**我删除了www.example.com中dotenv部分的所有代码，只添加了dotenv. load_dotenv（），成功地解决了所有问题。我不知道为什么会这样，但我几乎要哭了，因为我太高兴了。settings.py and just putting dotenv.load_dotenv(). I do not know why did that work but I am almost crying because of how happy I am.