单文件Django项目搭建

前面的Django官方教程 中学习到了使用django-admin startproject mysite 生成项目的方法。为了对Django有更加深入的理解，今天来一起研究下如何手动生成一个Django项目，为了使项目看起来简单，手动生成的时候要把所有代码整合进一个文件中。

新建空白文件

空白文件命名为：project_name.py。

加入入口文件namage.py中的代码

import os
import sys

if __name__ == "__main__":
    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "mysite.settings")
    try:
        from django.core.management import execute_from_command_line
    except ImportError as exc:
        raise ImportError(
            "Couldn't import Django. Are you sure it's installed and"
            "available on your PYTHONPATH environment variable? Did you"
            "forget to activate a virtual environment?"
        ) from exc
    execute_from_command_line(sys.argv)

以上代码是使用指令生成的，为了放进单文件，我们做如下优化：

• 去除了是否安装Django环境的异常处理
• 去除引入mysite.settings

将mysite.settings的内容直接加入单文件中

需要注意的事，mysite.settings包含的设置项非常的多，由于只是做学习，可以先将一些暂时用不到的设置全部删除。

"""
Django settings for mysite project.

Generated by 'django-admin startproject' using Django 2.0.1.

For more information on this file, see
https://docs.djangoproject.com/en/2.0/topics/settings/

For the full list of settings and their values, see
https://docs.djangoproject.com/en/2.0/ref/settings/
"""

import os

# Build paths inside the project like this: os.path.join(BASE_DIR, ...)
BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))


# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/2.0/howto/deployment/checklist/

# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = 'a()izd2o4^lj^6%w%9g7(^(1r4^o6(glwb8ks7)s8c8p6$p+$n'

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

ALLOWED_HOSTS = []


# Application definition

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
]

MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    '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 = 'mysite.urls'

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [],
        '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 = 'mysite.wsgi.application'


# Database
# https://docs.djangoproject.com/en/2.0/ref/settings/#databases

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.sqlite3',
        'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
    }
}


# Password validation
# https://docs.djangoproject.com/en/2.0/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/2.0/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/2.0/howto/static-files/

STATIC_URL = '/static/'

我们需要做的修改：

• 载入 from django.conf import settings
• 使用 settings.configure() 方法进行配置项设置
• 去除暂时不用的配置项目（后期用到时再添加）
• 将 ROOT_URLCONF 设置为当前文件，并将 URL 规则拷入到当前文件
• 去除 WSGI_APPLICATION 配置项目，并将 wsgi 的内容引入进来

import sys
from django.conf import settings

settings.configure(
    DEBUG=True,
    ROOT_URLCONF=__name__,
)

from django.contrib import admin
from django.urls import path

urlpatterns = [
    path('admin/', admin.site.urls),
]

from django.core.wsgi import get_wsgi_application
application = get_wsgi_application()

if __name__ == "__main__":
    from django.core.management import execute_from_command_line
    execute_from_command_line(sys.argv)

修改 url 路由规则，并建立视图

• 去除 admin 模块（这里用不到）
• 新建 index 视图（需要注意视图要放在 url 路由规则上方，否则会报错）
• 建立 url 规则与 index 视图的联系

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import sys
from django.conf import settings

settings.configure(
    DEBUG=True,
    ROOT_URLCONF=__name__,
)

from django.urls import path
from django.http import HttpResponse

def index(request):
    return HttpResponse("Hello World!")

urlpatterns = [
    path('index', index),
]

from django.core.wsgi import get_wsgi_application
application = get_wsgi_application()

if __name__ == "__main__":
    from django.core.management import execute_from_command_line
    execute_from_command_line(sys.argv)

至此，一个最简单的Django项目生成了，运行python project_name.py runserver 可看到执行效果。

把单文件作为模版来使用

上面完成的单文件，可以作为生成Django的模版使用，只需要在原先的指令后面加上 –template=project_name 即可。比如：

django-admin startproject mysite --template=project_name

注意，执行上面的生成指令要在 project_name 所在目录才行。