官方有很详细的文档，但是看过几遍之后如果要翻找还是有点麻烦，本文算作是学习笔记，提取一些关键点记录下来，另附上官方教程 Writing your first Django app
注： 文中的指令使用py，是在Windows上，macOS要使用 python3
1. 安装Django
Django 是一个基于 Python 的Web开发框架，安装前可以用下面的命令检查是否安装了 Django，如果已经安装，会显示版本，没有安装会提示没有该模块
py -m django --version如果没有安装，可以使用下面的命令安装
py -m pip install Django2. 创建项目
项目就是一个 project，一个项目可以包含多个 app，也可以理解为多个模块，创建项目使用如下命令，其中 mysite 是项目名称：
django-admin startproject mysite在令窗口中，切到刚刚创建的项目的根目录（有 manage.py），在项目中创建一个app，名字就叫 polls
py manage.py startapp polls然后修改几个文件
polls/views.py
from django.http import HttpResponse
def index(request):
return HttpResponse("Hello World!")polls/urls.py
from django.urls import path
from . import views
urlpatterns = [
path("", views.index, name="index"),
]mysite/urls.py
from django.contrib import admin
from django.urls import include, path
urlpatterns = [
path("polls/", include("polls.urls")),
path("admin/", admin.site.urls),
]最后启动服务，浏览器访问 http://localhost:8000/polls/
py manage.py runserver3. 配置语言和时区
项目配置在 mysite/settings.py
语言标识可以在这里查找 Language Identifiers (RFC 3066)
# 语言设置为中文
LANGUAGE_CODE = 'zh-Hans'时区标识可以在这里查找 List of tz database time zones
# 时区设置为北京时间
TIME_ZONE = 'Asia/Shanghai'4. 数据库
就使用自带的 SQLite 吧，方便又简单，如果开发商用的Web App，建议使用其他数据库，要进行额外的配置。
（1）创建数据模型
修改 polls/models.py
import datetime
from django.db import models
from django.utils import timezone
class Question(models.Model):
question_text = models.CharField(max_length=200)
pub_date = models.DateTimeField("date published")
def __str__(self):
return self.question_text
def was_published_recently(self):
return self.pub_date >= timezone.now() - datetime.timedelta(days=1)
class Choice(models.Model):
# Choice属于一个Question
question = models.ForeignKey(Question, on_delete=models.CASCADE)
choice_text = models.CharField(max_length=200)
votes = models.IntegerField(default=0)
def __str__(self):
return self.choice_text
（2）激活模型
修改 mysite/settings.py，在 INSTALLED_APP 中添加 polls.apps.PollsConfig
INSTALLED_APPS = [
"polls.apps.PollsConfig",
"django.contrib.admin",
"django.contrib.auth",
"django.contrib.contenttypes",
"django.contrib.sessions",
"django.contrib.messages",
"django.contrib.staticfiles",
]（3）创建数据迁移(尚未提交)
py manage.py makemigrations polls查看创建的迁移使用的SQL语句，下面命令中的 0001 是上面创建迁移时生成的 polls/migrations/0001_initial.py 文件名中的数字
py manage.py sqlmigrate polls 0001（4）提交迁移
py manage.py migrate总结起来就三步：修改模型 -> 创建迁移 -> 提交迁移
（5）玩转数据库API
打开交互式窗口
py manage.py shell>>> from polls.models import Choice, Question >>> Question.objects.all() <QuerySet []> >>> from django.utils import timezone >>> q = Question(question_text="What's new?", pub_date=timezone.now()) >>> q.save() >>> q.id 1 >>> q.question_text "What's new?" >>> q.pub_date datetime.datetime(2012, 2, 26, 13, 0, 0, 775217, tzinfo=datetime.timezone.utc) >>> q.question_text = "What's up?" >>> q.save() >>> Question.objects.all() <QuerySet [<Question: Question object (1)>]>
>>> from polls.models import Choice, Question
>>> Question.objects.all()
<QuerySet [<Question: What's up?>]>
>>> Question.objects.filter(id=1)
<QuerySet [<Question: What's up?>]>
>>> Question.objects.filter(question_text__startswith="What")
<QuerySet [<Question: What's up?>]>
>>> from django.utils import timezone
>>> current_year = timezone.now().year
>>> Question.objects.get(pub_date__year=current_year)
<Question: What's up?>
>>> Question.objects.get(id=2)
Traceback (most recent call last):
...
DoesNotExist: Question matching query does not exist.
>>> Question.objects.get(pk=1)
<Question: What's up?>
>>> q = Question.objects.get(pk=1)
>>> q.was_published_recently()
True
>>> q = Question.objects.get(pk=1)
>>> q.choice_set.all()
<QuerySet []>
>>> q.choice_set.create(choice_text="Not much", votes=0)
<Choice: Not much>
>>> q.choice_set.create(choice_text="The sky", votes=0)
<Choice: The sky>
>>> c = q.choice_set.create(choice_text="Just hacking again", votes=0)
>>> c.question
<Question: What's up?>
>>> q.choice_set.all()
<QuerySet [<Choice: Not much>, <Choice: The sky>, <Choice: Just hacking again>]>
>>> q.choice_set.count()
3
>>> Choice.objects.filter(question__pub_date__year=current_year)
<QuerySet [<Choice: Not much>, <Choice: The sky>, <Choice: Just hacking again>]>
>>> c = q.choice_set.filter(choice_text__startswith="Just hacking")
>>> c.delete()
5. 创建管理员
输入下面的命令，然后根据提示设置账户名，邮箱，密码
py manage.py createsuperuser启动服务，浏览器访问 http://127.0.0.1:8000/admin/
py manage.py runserver
修改 polls/admin.py 让管理员可管理数据
from django.contrib import admin
from .models import Question
admin.site.register(Question)管理员登录后
6. 使用 html 模板
（1）创建 HTML 文件
在 polls/ 目录下新建一个 templates 文件夹，在 polls\templates\ 目录下新建一个 polls 文件见，如果新建一个 HTML 文件，比如 index.html，其最终的路径为 mysite\polls\templates\polls\index.html，代码中将使用 polls\index.html
polls\templates\polls\index.html
{% if latest_question_list %}
<ul>
{% for question in latest_question_list %}
<li><a href="{% url 'index' question.id %}">{{ question.question_text }}</a></li>
{% endfor %}
</ul>
{% else %}
<p>No polls are available.</p>
{% endif %}polls\templates\polls\detail.html
<h1>{{ question.question_text }}</h1>
<ul>
{% for choice in question.choice_set.all %}
<li>{{ choice.choice_text }}</li>
{% endfor %}
</ul>（2）配置 view
修改 polls/views.py
from django.http import HttpResponse
from django.shortcuts import render, get_object_or_404
from .models import Question
def index(request):
latest_question_list = Question.objects.order_by("-pub_date")[:5]
context = {"latest_question_list": latest_question_list}
return render(request, "polls/index.html", context)
def detail(request, question_id):
question = get_object_or_404(Question, pk=question_id)
context = {"question": question}
return render(request, "polls/detail.html", context)
def results(request, question_id):
return HttpResponse("Results")
def vote(request, question_id):
return HttpResponse("Vote")（3）配置 url
修改 polls/urls.py
from django.urls import path
from . import views
urlpatterns = [
# ex: /polls/
path("", views.index, name="index"),
# ex: /polls/5/
path("<int:question_id>/", views.detail, name="detail"),
# ex: /polls/5/results/
path("<int:question_id>/results/", views.results, name="results"),
# ex: /polls/5/vote/
path("<int:question_id>/vote/", views.vote, name="vote"),
]（4）URL命名空间
当项目存在多个应用时，可能需要借助命名空间来确定url，在应用的 urls.py 中配置 app_name
from django.urls import path
from . import views
app_name = "polls"
urlpatterns = [
# ex: /polls/
path("", views.index, name="index"),
# ex: /polls/5/
path("<int:question_id>/", views.detail, name="detail"),
# ex: /polls/5/results/
path("<int:question_id>/results/", views.results, name="results"),
# ex: /polls/5/vote/
path("<int:question_id>/vote/", views.vote, name="vote"),
]index.html 中添加 app_name:
{% if latest_question_list %}
<ul>
{% for question in latest_question_list %}
<li><a href="{% url 'polls:index' question.id %}">{{ question.question_text }}</a></li>
{% endfor %}
</ul>
{% else %}
<p>No polls are available.</p>
{% endif %}
