python--18th Day Summary (Django Advanced)

First, the routing system

1. Each routing rule corresponds to a function in the view

123	url(r‘^index/(\d*)‘, views.index),url(r‘^manage/(?P<name>\w*)/(?P<id>\d*)‘, views.manage),url(r‘^manage/(?P<name>\w*)‘, views.manage,{‘id‘:333}),

2, according to the app to classify the rules

1	url(r‘^web/‘,include(‘web.urls‘)),

The routing system in Django differs from the framework of other languages in that the URL for each request in Django has a route map so that the request can be handed to the function in the view for processing. Most other web frameworks are a route map for a class of URL requests, which makes the routing system concise.

A dynamic routing system demo for Django is developed through the reflection mechanism:
Second, the middleware

Middleware_classes = (
' Django.contrib.sessions.middleware.SessionMiddleware ',
' Django.middleware.common.CommonMiddleware ',
' Django.middleware.csrf.CsrfViewMiddleware ',
' Django.contrib.auth.middleware.AuthenticationMiddleware ',
' Django.contrib.auth.middleware.SessionAuthenticationMiddleware ',
' Django.contrib.messages.middleware.MessageMiddleware ',
' Django.middleware.clickjacking.XFrameOptionsMiddleware ',
' Django.middleware.security.SecurityMiddleware ',
' Middleware.middle1.mmm ',
' Middleware.middle1.xxx ',
)
Process_request_list = []
Process_view_list = []
Process_response_list = []
Process_exception_list = []

For class in middleware_classes:
obj = Class ()
There are process_request methods in if obj:
Process_request_list.append (Obj.process_request)

For I in Process_request_list:
I ()
For I in Process_view_list:
I ()

The function in views

For I in Process_response_list:
I ()
Obj.process_request


Three, Model (*)
1. Create a table
2. Operation table Data

Django uses a new approach, namely: Relational object Mapping (object relational Mapping, or ORM).

Php:activerecord

Java:hibernate

C#:entity Framework

Django follows the code Frist principle of automatically generating database tables based on classes defined in your code.

1, create the model, then you can create a database table according to the model

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from django.db import models class userinfo(models.Model):    name = models.CharField(max_length=30)    email = models.EmailField()    memo = models.TextField()

2. Connecting table relationship:

• A pair of more, models. ForeignKey (Colordic)
• One on one, models. Onetoonefield (Onemodel)
• Many-to-many, authors = models. Manytomanyfield (Author)

Application Scenarios:

• One to one: when you create a row of data in a table, there is a single-selection drop-down box (the contents of the drop-down box are used once and disappear).
  For example, a table containing 10 columns of data holds relevant information, and after a period of time, 10 columns do not meet the requirements and need to add 5 columns of data to the original table.
• One-to-many: when a row of data is created in a table, there is a single-selection drop-down box (which can be selected repeatedly).
  For example: When creating user information, you need to select a user type "ordinary user" "Gold user" "Platinum User" and so on.
• Many-to-many: a row of data is created in a table, and there is a drop-down box that you can choose from.
  For example, to create user information, you need to specify multiple hobbies for the user.

3. Database operation

• Add: Create an instance and call save
• Update: A. Get instance, then Sava;b.update (Specify column)
• Delete: A. Filter (). Delete (); B.all (). Delete ()
• Get: A. Single =get (id=1); b. all = All ()
• Filtering: Filter (name= ' xxx '), filter (name__contains= ");(id__in = [[+]]);
  Icontains (case-insensitive like), StartsWith and EndsWith, and range (sqlbetween query) ' GT ', ' in ', ' isnull ', ' endswith ', ' contains ', ' lt ', ' StartsWith ', ' iendswith ', ' icontains ', ' range ', ' istartswith '
• Sort: order_by ("name") =asc; order_by ("-name") =desc
• Return to article n-m: article n [0]; top two [0:2]
• Specify mappings: Values
• Quantity: Count ()
• Aggregation: From django.db.models import Min,max,sum Objects.all (). Aggregate (Max (' guest_id '))
• Raw SQL
  

  123	cursor =connection.cursor()cursor.execute(‘‘‘SELECT DISTINCT first_name ROM people_person WHERE last_name = %s""", [‘Lennon‘])row =cursor.fetchone()

Iv. Form (*)
1. User submitted data validation
2. Generate HTML tags

#!/usr/bin/env python#-*-coding:utf-8-*-ImportRe fromDjangoImportForms fromDjango.core.exceptionsImportValidationErrordefmobile_validate (value): Mobile_re= Re.compile (r'^ (13[0-9]|15[012356789]|17[678]|18[0-9]|14[57]) [0-9]{8}$')    if  notMobile_re.match (value):RaiseValidationError ('cell phone number format error')classPublishForm (forms. Form): User_type_choice=((0, U'Normal User'),        (1, U'Advanced users'),) User_type= Forms. Integerfield (Widget=forms.widgets.select (choices=User_type_choice, Attrs={'class':"Form-control"})) title= Forms. Charfield (max_length=20, Min_length=5, Error_messages={'Required': U'title cannot be empty',                                            'Min_length': U'The title is a minimum of 5 characters',                                            'Max_length': U'title up to 20 characters'}, Widget=forms. TextInput (attrs={'class':"Form-control",                                                          'placeholder': U'title 5-20 characters'}) Memo= Forms. Charfield (required=False, Max_length=256, Widgets=forms.widgets.textarea (attrs={'class':"Form-control No-radius",'placeholder': U'Detailed Description','rows': 3})) Phone= Forms. Charfield (validators=[Mobile_validate,], error_messages={'Required': U'The phone cannot be empty'}, Widget=forms. TextInput (attrs={'class':"Form-control",                                                          'placeholder': U'Mobile phone number'})) Email= Forms. Emailfield (required=False, Error_messages={'Required': U'The mailbox cannot be empty','Invalid': U'Bad mailbox Format'}, Widget=forms. TextInput (attrs={'class':"Form-control",'placeholder': U'Email'}))defPublish (Request): RET= {'Status': False,'Data':"','Error':"','Summary':"'}    ifRequest.method = ='POST': Request_form=PublishForm (Request. POST)ifrequest_form.is_valid (): Request_dict=Request_form.clean ()Printrequest_dict ret['Status'] =TrueElse: Error_msg=Request_form.errors.as_json () ret['Error'] =json.loads (error_msg)returnHttpResponse (Json.dumps (ret))

V. Cookies and Session

First, the operation of cookies

Gets the cookie:request. Cookies[key]

Set Cookie:response.set_cookie (Key,value)

Because cookies are stored on the client's computer, jquery can also manipulate cookies.

12	<script src=‘/static/js/jquery.cookie.js‘></script>$.cookie("list_pager_num", 30,{ path: ‘/‘});

Second, the Operation session

Get Session:request.session[key]

Set Session:reqeust.session[key] = value

Delete Session:del Request[key]

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request.session.set_expiry(value)*如果value是个整数，session会在些秒数后失效。* 如果value是个datatime或timedelta，session就会在这个时间后失效。* 如果value是0,用户关闭浏览器session就会失效。*如果value是None,session会依赖全局session失效策略。

See MORE:

https://docs.djangoproject.com/en/1.9/topics/http/sessions/

http://docs.30c.org/djangobook2/chapter14/

https://docs.djangoproject.com/en/1.9/ref/settings/#settings-sessions

Third, the application

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def login(func):    def wrap(request, *args, **kwargs):        # 如果未登陆，跳转到指定页面        if request.path == ‘/test/‘:            return redirect(‘http://www.baidu.com‘)        return func(request, *args, **kwargs)    return wrap

python--18th Day Summary (Django Advanced)