django搭建web網(wǎng)站

首先我們聊一下django的前世今生司澎，據(jù)說03年的時(shí)候下面這幾家公司開始使用python構(gòu)建網(wǎng)站，
Lawrence Journal-World newspaper
Adrian Holovaty
Simon Willison
這幾家公司的工作性質(zhì)都有一個(gè)共同的特點(diǎn)就是每天需要不停的處理各類新聞事務(wù)栋豫、作品挤安，話說當(dāng)時(shí)編輯部門提出的需求變化之快讓技術(shù)部門毫無招架之力，所以django就在這年誕生了丧鸯，django與其快速開發(fā)的特性蛤铜，方便的model管理，MTV模型（model-template-view）成就了djano在python web領(lǐng)域的霸主地位丛肢，下面的演示將帶大家一起領(lǐng)略django的神奇魅力围肥。

步驟

1、環(huán)境準(zhǔn)備蜂怎，安裝django3.0版本,mysql驅(qū)動(dòng)
2穆刻、創(chuàng)建一個(gè)項(xiàng)目，并設(shè)置settings
3杠步、初始化數(shù)據(jù)庫氢伟，創(chuàng)建django超級(jí)用戶用于后臺(tái)model管理
4撰洗、創(chuàng)建一個(gè)app，在settings注冊(cè)app,在models.py創(chuàng)建模型,并在admin.py注冊(cè)model,生成遷移文件并同步到數(shù)據(jù)庫
5腐芍、app下views創(chuàng)建視圖層
6差导、app下創(chuàng)建urls路由配置文件，并為視圖層配置跳轉(zhuǎn)
7猪勇、app下創(chuàng)建templates/appName/結(jié)構(gòu)目錄设褐，并在目錄下創(chuàng)建視圖層對(duì)應(yīng)的html模板
8、效果展示
9泣刹、使用django view模板助析，簡化代碼量
10、static靜態(tài)資源使用

1椅您、安裝django3.0版本外冀，指定安裝源為國內(nèi)豆瓣源

pip install django==3.0 -i http://pypi.douban.com/simple --trusted-host pypi.douban.com
pip install  -i http://pypi.douban.com/simple --trusted-host pypi.douban.com mysqlclient

django-admin startproject djangotest

2、settings.py設(shè)置

# 設(shè)置顯示語言
from django.utils.translation import gettext_lazy as _
LANGUAGES = [
    ('zh-Hans', _('Chinese')),
]
LANGUAGE_CODE = 'zh-Hans'

# 設(shè)置時(shí)區(qū)
TIME_ZONE = 'Asia/Shanghai'

# 設(shè)置數(shù)據(jù)庫掀泳，默認(rèn)使用sqlite3雪隧，這里使用mysql
DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': 'django',
        'USER': 'root',
        'PASSWORD': 'root',
        'HOST': '127.0.0.1',
        'PORT': '3306',
    }
}

3、初始化數(shù)據(jù)庫
3-1 在數(shù)據(jù)庫執(zhí)行下面命令創(chuàng)建django庫

 create database django default charset utf8;

3-2 在項(xiàng)目下執(zhí)行python manage.py migrate 同步django后臺(tái)管理的相關(guān)表

image.png

3-3 創(chuàng)建超級(jí)用戶用于django后臺(tái)登陸员舵，管理model

python manage.py createsuperuser

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3-4 啟動(dòng)項(xiàng)目,訪問http://127.0.0.1:8000脑沿，http://127.0.0.1:8000/admin

python manage.py runserver

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4、創(chuàng)建一個(gè)app马僻，在settings注冊(cè)app,在models.py創(chuàng)建模型,并在admin.py注冊(cè)model,生成遷移文件并同步到數(shù)據(jù)庫

4-1 創(chuàng)建一個(gè)民意調(diào)查的app,需求庄拇，我們需要對(duì)網(wǎng)友關(guān)注的問題進(jìn)行網(wǎng)絡(luò)投票，一個(gè)問題對(duì)應(yīng)多種答案韭邓，每個(gè)網(wǎng)民可以對(duì)其中的一個(gè)答案進(jìn)行投票
python manage.py startapp polls

image.png

4-2 在settings.py INSTALLED_APPS增加polls app

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

4-3 models.py創(chuàng)建model模型

from django.db import models

# 繼承Model措近，django會(huì)自動(dòng)識(shí)別并在數(shù)據(jù)庫創(chuàng)建該表
class Question(models.Model):
    question_text = models.CharField(max_length=200)
    pub_date = models.DateTimeField('date published')
    
    # 用于django后臺(tái)顯示該字段
    def __str__(self):
        return self.question_text

class Choice(models.Model):
    # 一對(duì)多關(guān)系，刪除question時(shí)女淑，對(duì)應(yīng)的choice也會(huì)刪除
    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

4-4 admin.py注冊(cè) model

from django.contrib import admin
from .models import Question, Choice
admin.site.register(Question)
admin.site.register(Choice)

4-5 生成遷移文件瞭郑，并同步到數(shù)據(jù)庫

python manage.py makemigrations
python manage.py migrate

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4-6 后臺(tái)可以看到已更新剛注冊(cè)的model

image.png

4-7 增加幾個(gè)quesiton，并對(duì)question設(shè)置幾個(gè)選項(xiàng)

image.png

5诗力、polls/views.py創(chuàng)建視圖層

from django.shortcuts import render, get_object_or_404
from django.http import HttpResponseRedirect
from .models import Question, Choice
from django.urls import reverse

# 獲取最近相關(guān)的5個(gè)問題
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)

# 投票頁面
def detail(request, question_id):
    question = get_object_or_404(Question, pk=question_id)
    return render(request, 'polls/detail.html', {'question': question})

# 投票處理
def vote(request, question_id):
    question = get_object_or_404(Question, pk=question_id)
    try:
        # POST請(qǐng)求的key需要與detail.html input name屬性保持一致
        selected_choice = question.choice_set.get(pk=request.POST['choice'])
    except(KeyError, Choice.DoesNotExist):
        return render(request, 'polls/detail.html',{
            'question':question,
            'error_message': "You didn't select a choice"
        })
    else:
        selected_choice.votes += 1
        selected_choice.save()
        return HttpResponseRedirect(reverse('polls:results', args=(question.id,)))

# 投票結(jié)果展示
def results(request, question_id):
    question = get_object_or_404(Question, pk=question_id)
    return render(request, 'polls/results.html', {'question':question})

6凰浮、app下創(chuàng)建urls.py路由配置文件我抠，并為視圖層配置跳轉(zhuǎn)

from django.urls import path
from . import views

# app命名空間苇本，django一個(gè)項(xiàng)目包含n個(gè)app，使用命名可以可以對(duì)url進(jìn)行分類
app_name = 'polls'
urlpatterns =  [
    path('', views.index, name='index'),
    path('<int:question_id>/', views.detail, name='detail'),
    path('<int:question_id>/vote/', views.vote, name='vote'),
    path('<int:question_id>/results/', views.results, name='results'),
]

項(xiàng)目路由配置

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

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

image.png

7菜拓、app下創(chuàng)建templates/appName/結(jié)構(gòu)目錄瓣窄，并在目錄下創(chuàng)建視圖層對(duì)應(yīng)的html模板,下面的是django模板的固定寫法.

image.png

index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
{% if latest_question_list %}
    <ul>
        {% for question in latest_question_list %}
            <li> <a href="{% url 'polls:detail' question.id %}">{{ question.question_text }}</a> </li>
        {% endfor %}
    </ul>
{% else %}
    <p> don't have resources </p>
{% endif %}
</body>
</html>

detail.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<h1> {{ question.question_text }} </h1>
{% if error_message %} <p> <strong> {{ error_message }} </strong> </p> {% endif %}
<form action="{% url 'polls:vote' question.id %}" method="post">
    {% csrf_token %}
    <ul>
        {% for choice in question.choice_set.all %}
            <input type="radio" name="choice" id="choice{{ forloop.counter }}" value="{{ choice.id }}">
            <label for="choice{{ forloop.counter }}"> {{ choice.choice_text }} </label>
        {% endfor %}
    </ul>
    <input type="submit" value="Vote">
</form>

</body>
</html>

results.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<h1> {{ question.question_text }} </h1>

<ul>
    {% for choice in question.choice_set.all %}
        <li> {{ choice.choice_text }} -- {{ choice.votes }} </li>
    {% endfor %}
</ul>
<a href="{% url 'polls:vote' question.id %}"> Vote again? </a>
</body>
</html>

8、效果展示

index首頁

image.png

投票頁面

image.png

結(jié)果展示頁面

image.png

9纳鼎、django為單個(gè)model或model list集合提供了模板俺夕，對(duì)于上面的index,detail,results裳凸，都是查詢model或model集合，下面對(duì)這些view進(jìn)行簡化

9-1 修改views.py, urls.py如下

views.py
from django.http import HttpResponseRedirect
from django.urls import reverse
from django.shortcuts import get_object_or_404, render
from django.views import generic
from .models import Question, Choice

class IndexView(generic.ListView):
    template_name = 'polls/index.html'
    context_object_name = 'latest_question_list'

    def get_queryset(self):
        return Question.objects.order_by('-pub_date')[:5]

# django DetailView模板 默認(rèn)返回的是<app name>/<model name>_detail.html,你甚至可以不指定template_name劝贸，
# 只要你按照相應(yīng)的規(guī)則創(chuàng)建html
class DetailView(generic.DetailView):
    model = Question
    template_name = 'polls/detail.html'

class ResultsView(generic.DetailView):
    model = Question
    template_name = 'polls/results.html'

def vote(request, question_id):
    question = get_object_or_404(Question, pk=question_id)
    try:
        # POST請(qǐng)求的key需要與detail.html input name屬性保持一致
        selected_choice = question.choice_set.get(pk=request.POST['choice'])
    except(KeyError, Choice.DoesNotExist):
        return render(request, 'polls/detail.html',{
            'question':question,
            'error_message': "You didn't select a choice"
        })
    else:
        selected_choice.votes += 1
        selected_choice.save()
        return HttpResponseRedirect(reverse('polls:results', args=(question.id,)))


urls.py
from django.urls import path
from . import views

app_name = 'polls'

# 這里使用主鍵代替上面的question_id
urlpatterns = [
    path('', views.IndexView.as_view(), name='index'),
    path('<int:pk>/', views.DetailView.as_view(), name='detail'),
    path('<int:pk>/results/', views.ResultsView.as_view(), name='results'),
    path('<int:question_id>/vote/', views.vote, name='vote'),
]

10姨谷、django給我們每一個(gè)app提供了靜態(tài)資源的管理，創(chuàng)建<app name>/static/<app name>/style.css

image.png

index.html引用樣式

{% load static %}
<link rel="stylesheet" type="text/css" href="{% static 'polls/style.css' %}">

image.png