Python自動化開發學習的第十一周----WEB框架--Django基礎
WEB框架的本質
對於所有的Web應用，本質上其實就是一個socket服務端，用戶的瀏覽器其實就是一個socket客戶端。
#!/usr/bin/env python
#coding:utf-8
import socket
def handle_request(client):
buf = client.recv(1024)
client.send("HTTP/1.1 200 OK\r\n\r\n")
client.send("Hello, Seven")
def main():
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.bind((‘localhost‘,8000))
sock.listen(5)
while True:
connection, address = sock.accept()
handle_request(connection)
connection.close()
if __name__ == ‘__main__‘:
main()
上述通過socket來實現了其本質，而對於真實開發中的python web程序來說，一般會分為兩部分：服務器程序和應用程序。服務器程序負責對socket服務器進行封裝，並在請求到來時，對請求的各種數據進行整理。應用程序則負責具體的邏輯處理。為了方便應用程序的開發，就出現了眾多的Web框架，例如：Django、Flask、web.py 等。不同的框架有不同的開發方式，但是無論如何，開發出的應用程序都要和服務器程序配合，才能為用戶提供服務。這樣，服務器程序就需要為不同的框架提供不同的支持。這樣混亂的局面無論對於服務器還是框架，都是不好的。對服務器來說，需要支持各種不同框架，對框架來說，只有支持它的服務器才能被開發出的應用使用。這時候，標準化就變得尤為重要。我們可以設立一個標準，只要服務器程序支持這個標準，框架也支持這個標準，那麽他們就可以配合使用。一旦標準確定，雙方各自實現。這樣，服務器可以支持更多支持標準的框架，框架也可以使用更多支持標準的服務器。
WSGI（Web Server Gateway Interface）是一種規範，它定義了使用python編寫的web app與web server之間接口格式，實現web app與web server間的解耦。
python標準庫提供的獨立WSGI服務器稱為wsgiref。
from wsgiref.simple_server import make_server
def RunServer(environ, start_response):
start_response(‘200 OK‘, [(‘Content-Type‘, ‘text/html‘)])
return [bytes(‘<h1>Hello, web!</h1>‘, encoding=‘utf-8‘), ]
if __name__ == ‘__main__‘:
httpd = make_server(‘‘, 8000, RunServer)
print("Serving HTTP on port 8000...")
httpd.serve_forever()
Python的WEB框架有Django、Tornado、Flask 等多種，Django相較與其他WEB框架其優勢為：大而全，框架本身集成了ORM、模型綁定、模板引擎、緩存、Session等諸多功能。
Django工程前基本配置
一、安裝Django
pip install django
二、創建Django工程
- 終端命令：django-admin startproject sitename（工程名稱）
- IDE創建Django程序時，本質上都是自動執行上述命令
三、程序目錄
mysite
- mysite # 對整個程序進行配置
- init
- settings # 配置文件
- url # URL對應關系
- wsgi # 遵循WSIG規範，uwsgi + nginx
- manage.py # 管理Django程序：
- python manage.py
- python manage.py startapp xx
- python manage.py makemigrations
- python manage.py migrate
-templates #放置網頁內容
# 運行Django功能
python manage.py runserver 127.0.0.1:8000
四、創建app
# 創建app
python manage.py startapp cmdb
python manage.py startapp openstack
python manage.py startapp xxoo....
app：
migrations 數據修改表結構
admin Django為我們提供的後臺管理
apps 配置當前app
models ORM,寫指定的類 通過命令可以創建數據庫結構
tests 單元測試
views 業務代碼
五、工程前的默認配置
1.配置模板的路徑
settings.py
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 = ‘s14day19.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‘,
],
},
},
]
2.配置靜態目錄
新建static目錄
settings.py中添加
STATIC_URL = ‘/static/‘
STATICFILES_DIRS = (
os.path.join(BASE_DIR,"static"),
)
下面就可以編寫程序了
編寫程序
Django請求生命周期
-> URL對應關系（匹配） -> 視圖函數 -> 返回用戶字符串
-> URL對應關系（匹配） -> 視圖函數 -> 打開一個HTML文件，讀取內容
路由系統
1.url
urls.py
from django.contrib import admin
from django.urls import path
from cmdb import views
urlpatterns = [
path(‘admin/‘, admin.site.urls),
path(‘login/‘, views.login),
path(‘home/‘, views.home),
]
2.基於正則表達式的url
re_path(‘detail-(\d+).html‘, views.detail), #一個函數對應多個頁面 re_path(‘detail-(\d+)-(\d+).html‘, views.detail), #nid ,uid 一定按照順序 re_path(‘detail-(?P<nid>\d+)-(?P<uid>\d+).html‘, views.detail), #綁定nid和uid
1 # def detail(request,nid): 2 # return HttpResponse(nid) 3 # # n = request.GET.get("nid") 4 # 5 # # info = USER_DICT[nid] 6 # # return render(request,"detail.html",{"info":info}) 7 # def detail(request, nid): 8 # info = USER_DICT[nid] 9 # return render(request,"detail.html",{"info":info}) 10 def detail(request,nid,uid): 11 print(nid,uid) 12 13 return HttpResponse(nid) 14 # info = USER_DICT[nid] 15 # return render(request,"detail.html",{"info":info})views
1 <!DOCTYPE html> 2 <html lang="en"> 3 <head> 4 <meta charset="UTF-8"> 5 <title>Title</title> 6 </head> 7 <body> 8 {{ user_dict.user }} 9 <ul> 10 {% for k,row in user_dict.items %} 11 <li><a target="_blank" href="/detail-{{ k }}.html">{{ row.user }}</a></li> 12 {% endfor %} 13 </ul> 14 <!-- 15 <ul> 16 {% for k,row in user_dict.items %} 17 <li><a target="_blank" href="/detail/?nid={{ k }}">{{ row.user }}</a></li> 18 {% endfor %} 19 </ul> 20 --> 21 22 </body> 23 </html>index.html
1 <!DOCTYPE html> 2 <html lang="en"> 3 <head> 4 <meta charset="UTF-8"> 5 <title>Title</title> 6 </head> 7 <body> 8 <h1>詳細信息</h1> 9 <h3>用戶名：{{ info.user }}</h3> 10 <h3>密碼：{{ info.password }}</h3> 11 <h3>郵箱：{{ info.email }}</h3> 12 13 </body> 14 </html>detail.html
3.為路由映射設置名稱
對URL路由關系進行命名， ***** 以後可以根據此名稱生成自己想要的URL *****
urls.py
urlpatterns = [
path(‘indfasfasdfdex/‘, views.index, name="index1"),
re_path(‘ind/(\d+)/‘, views.index, name="index2"),
re_path(‘ind/(\d+)/(\d+)/‘, views.index, name="index3"),
re_path(‘ind/(?P<nid>\d+)/(?P<uid>\d+)/‘, views.index, name="index4"),
]
views.py
def func(request, *args, **kwargs):
from django.urls import reverse
url1 = reverse(‘index1‘) # indefasfasdfdex/
url2 = reverse(‘index3‘, args=(1,2,)) # ind/1/2/
url3 = reverse(‘index4‘, kwargs={‘pid‘: 1, "nid": 9}) #ind/1/9/
xxx.html
{% url "index1" %} # indfasfasdfdex/
{% url "index2" 1 2 %} # ind/1/2/
{% url "index3" pid=1 nid=9 %} # ind/1/9/
註：
# 當前的URL
request.path_info
4.路由分發-----多級路由
主目錄下的urls.py
urlpatterns = [
path(‘cmdb/‘,include("app01.urls")),
path(‘monitor/‘,include("app02.urls"))
]
app01下添加urls.py
from django.urls import path,re_path
from app01 import views
urlpatterns = [
path(‘index/‘, views.index),
]
app02下添加urls.py
from django.urls import path,re_path
from app02 import views
urlpatterns = [
path(‘index/‘, views.index),
]
視圖
views.py
def func(request):
# 包含所有的請求數據
...
return HttpResponse(‘字符串‘)
return render(request, ‘index.html‘, {‘‘})
retrun redirect(‘URL‘)
from django.shortcuts import render
from django.shortcuts import HttpResponse
from django.shortcuts import redirect
USER_LIST=[
{"username":"zhangsan","gender":"man","email":"[email protected]"},
{"username":"zhangsi","gender":"woman","email":"[email protected]"},
{"username":"zhangwu","gender":"man","email":"[email protected]"},
]
def home(request):
print(request.method)
if request.method == "POST":
user=request.POST.get("username")
gen=request.POST.get("gender")
ema=request.POST.get("email")
temp = {"username":user,"gender":gen,"email":ema}
USER_LIST.append(temp)
return render(request,"home.html",{"user_list":USER_LIST})
def login(request):
# f = open("templates/login.html","r",encoding="utf-8")
# date = f.read()
# f.close()
error_msg = " "
if request.method == "POST":
user = request.POST.get("user",None)
pwd = request.POST.get("pwd",None)
if user=="root" and pwd=="123":
return redirect("http://www.baidu.com")
else:
error_msg = "用戶名密碼錯誤"
return render(request,"login.html",{"error_msg":error_msg})
獲取多數據和文件上傳
1 <!DOCTYPE html> 2 <html lang="en"> 3 <head> 4 <meta charset="UTF-8"> 5 <title>Title</title> 6 </head> 7 <body> 8 <form action="/login/" method="POST" enctype="multipart/form-data"> 9 <p> 10 <input type="text" name="user" placeholder="用戶名" /> 11 </p> 12 <p> 13 <input type="password" name="password" placeholder="密碼" /> 14 </p> 15 <p> 16 男：<input type="radio" name="gender" value="1"/> 17 女：<input type="radio" name="gender" value="2"/> 18 </p> 19 <p> 20 籃球：<input type="checkbox" name="faver" value="11" /> 21 足球：<input type="checkbox" name="faver" value="22" /> 22 排球：<input type="checkbox" name="faver" value="33" /> 23 </p> 24 <p> 25 <select name="city" multiple> 26 <option value="bj">北京</option> 27 <option value="sh">上海</option> 28 <option value="tj">天津</option> 29 </select> 30 </p> 31 <p> 32 <input type="file" name="filesss"/> 33 </p> 34 <p> 35 <input type="submit" value="提交" /> 36 </p> 37 </form> 38 </body> 39 </html>login.html
1 from django.shortcuts import render,HttpResponse,redirect 2 3 # Create your views here. 4 5 def index(request): 6 return HttpResponse("Welcome to Index!") 7 8 def login(request): 9 ‘‘‘if request.method == "GET": 10 return render(request, "login.html") 11 elif request.method == "POST": 12 u= request.POST.get("user") 13 p= request.POST.get("password") 14 15 if u == "abc" and p == "123": 16 return redirect("/index/") 17 else: 18 return render(request,"login.html") 19 else: 20 return redirect("/index/") 21 ‘‘‘ 22 23 if request.method == "GET": 24 return render(request, "login.html") 25 elif request.method == "POST": 26 # v = request.POST.get("gender") 27 # print(v) 28 # v = request.POST.getlist("faver") 29 # print(v) 30 # v = request.POST.getlist("city") 31 # print(v) 32 33 # 文件上傳 34 obj =request.FILES.get("filesss") 35 import os 36 file_path = os.path.join("upload",obj.name) 37 f= open(file_path,mode="wb") 38 for i in obj.chunks(): 39 f.write(i) 40 f.close() 41 42 43 44 return render(request, "login.html") 45 else: 46 return redirect("/index/")views.py
FBV & CBV
url.py index ---> 函數名
views.py def 函數（request）:................
FBV /index/ -> 函數名
CBV /index/ -> 類
from django.views import View
class Home(View):
def get(self,request):
print(request.method)
return render(request,"home.html")
def post(self,request):
print(request.method,"post")
return render(request, "home.html")
模板
模板語言
return render(request, ‘index.html‘, {‘li‘: [11,22,33]})
{% for item in li %}
<h1>{{item}}</h1>
{% endfor %}
*********** 索引用點 **********
<h2> {{item.0 }} </h2>
1 <!DOCTYPE html> 2 <html lang="en"> 3 <head> 4 <meta charset="UTF-8"> 5 <title>Title</title> 6 </head> 7 <body style="margin: 0"> 8 <div style="background-color: #eeeeee;height: 50px;"></div> 9 <form action="/home/" method="post"> 10 <p> 11 <input type="text" name="username" placeholder="用戶名" /> 12 </p> 13 <p> 14 <input type="text" name="gender" placeholder="性別" /> 15 </p> 16 <p> 17 <input type="text" name="email" placeholder="郵箱" /> 18 </p> 19 <p> 20 <input type="submit" value="提交" /> 21 </p> 22 </form> 23 <div> 24 <table> 25 {% for row in user_list %} 26 <tr> 27 <td>{{ row.username }}</td> 28 <td>{{ row.gender }}</td> 29 <td>{{ row.email }}</td> 30 </tr> 31 {% endfor %} 32 </table> 33 </div> 34 </body> 35 </html>home
1 <!DOCTYPE html> 2 <html lang="en"> 3 <head> 4 <meta charset="UTF-8"> 5 <title>Title</title> 6 <link rel="stylesheet" href="/static/commons.css" /> 7 <style> 8 label{ 9 width: 80px; 10 text-align: right; 11 display: inline-block; 12 } 13 </style> 14 </head> 15 <body> 16 <form action="/login/" method="post"> 17 <p> 18 <label for="username">用戶名：</label> 19 <input id="username" name="user" type="text" /> 20 </p> 21 <p> 22 <label for="password">密碼：</label> 23 <input id="password" name="pwd" type="text" /> 24 <input type="submit" value="提交" /> 25 <span style="color: red">{{ error_msg }}</span> 26 </p> 27 </form> 28 <script src="/static/jquery-1.12.4.js"></script> 29 </body> 30 </html>login
ORM操作
*******************************To Be Continue************************************
Python自動化開發學習的第十一周----WEB框架--Django基礎