Deepen the understanding of Django by interview questions
- 2021-07-22 10:39:18
- OfStack
1. What do you know about Django?
#1.Django Is to go in a big and comprehensive direction, and it is best known for its fully automated management background: it only needs to use ORM Do simple object definition, it can automatically generate database structure, as well as a full-featured management background.
#2.Django Built-in ORM It is highly coupled with other modules in the framework.
# Applications must use the Django Built-in ORM Otherwise, you will not be able to enjoy all kinds of services provided within the framework based on its ORM The convenience of;
# Theoretically, it can be switched off ORM Module, but this is equivalent to demolishing and redecorating the renovated house. It is better to 1 At the beginning, the hair embryo room was completely renovated.
#3.Django Its selling point is ultra-high development efficiency and its performance expansion is limited; Adopt Django The project, when the traffic reaches 1 After the scale is fixed, it needs to be reconstructed to meet the performance requirements.
#4.Django It is suitable for small and medium-sized websites, or as a tool for large websites to quickly realize the prototype of products.
#5.Django The design philosophy of template is to completely separate code and style; Django The possibility of coding and processing data in templates is fundamentally eliminated. 2. Comparison of Django, Flask and Tornado
#1.Django Take a big and comprehensive direction , High development efficiency. Its MTV Framework , Bring your own ORM,admin Background management , Bring your own sqlite Database and server for development test
# It improves the super high development efficiency for developers
#2.Flask Is a lightweight framework , Freedom , Flexible , Strong scalability , Core is based on Werkzeug WSGI Tools and jinja2 Template engine
#3.Tornado Going in the direction of less and more precision , Superior performance. It is best known for its asynchronous non-blocking design
#Tornado Two core modules of:
# 1.iostraem For non-blocking socket Simple encapsulation
# 2.ioloop : Right I/O Multiplexed encapsulation, which implements the 1 Singleton 3. What are wsgi, uwsgi, uWSGI?
#WSGI:
# web Server gateway interface , Yes 1 Set of agreements. Used to receive the user request, encapsulate the request for the first time, and then hand the request to the web Framework
# Realization wsgi Modules of the protocol:
# 1.wsgiref, Is essentially writing 1 A socket Server for receiving user requests (django)
# 2.werkzeug, Is essentially writing 1 A socket Server for receiving user requests (flask)
#uwsgi:
# And WSGI1 Sample is 1 A communication protocol, which is uWSGI Exclusive protocol of server , Used to define the type of information to be transmitted
#uWSGI:
# Yes 1 A web Server , Realized WSGI Agreement ,uWSGI Agreement ,http Agreement ,4. What is the lifecycle of an django request?
#1.wsgi, The request is encapsulated and handed to web Framework ( Flask , Django )
#2. Middleware, which validates the request or adds other relevant data to the request object, such as: csrf , request.session -
#3. Route matching Depending on what the browser sends url To match different view functions
#4. View function, in which business logic is processed, may involve: orm , templates => Render -
#5. Middleware, which processes the response data.
#6.wsgi, Sends the content of the response to the browser. 5. What are FBV and CBV?
#FBV And CBV The essence is 1 Like
# Function-based views are called FBV The class-based view is called CBV
# In python Use in CBV Advantages of:
#1. Improve the reusability of code and use object-oriented technologies, such as Mixin (Multiple inheritance)
#2. You can use different functions for different HTTP Method, not through many if Judge and improve code readability 6. How do I add a decorator to my CBV program?
# Introduce method_decorator Module
#1. Adding a decorator directly to the class
#@method_decorator(test,name='dispatch')
#class Loginview(View):
# pass
#2. Add a decorator directly in front of the processed function
#@method_decorator(test)
# def post(self,request,*args,**kwargs):pass7. Brief introduction of MVC and MTV
#MVC Software system is divided into 3 Basic parts: model (Model) , view (View) And controller (Controller)
#Model Responsible for mapping business objects to databases (ORM)
#View : Responsible for interaction with users
#Control Accept the user's input, call the model and view to complete the user's request
#Django Framed MTV The design pattern draws on the MVC The idea of framework ,3 The sections are: Model , Template And View
#Model( Model ) Objects responsible for business objects and databases (ORM)
#Template( Template ) Responsible for presenting the page to the user
#View( View ) Is responsible for the business logic and calls the Model And Template
# In addition ,Django And 1 A urls Dispenser ,
# It will 1 All URL Page requests for distribution to different view Deal with ,view And then call the corresponding Model And Template8. The role of name in django routing system?
# Used to reverse resolve routes , Equivalent to giving url Take an alias, as long as the name remains unchanged , Even if the corresponding url Change
# This article can also be found by this name url9. List the built-in components of django?
#1.Admin That's right model Add, delete, modify and query the provided components for the corresponding data table in
#2.model Component: Responsible for operating the database
#3.form Components: 1. Generate HTML Code 2. Data validity check 3 Verification information is returned and displayed
#4.ModelForm Component is used for database operations , It can also be used for authentication of user requests 10. What are the functions and application scenarios of Django and MIDDLEWARES middleware?
# Middleware is between request And response Between processing 1 Channel processing process , Used to change globally Django The input and output of the.
# Simply put, middleware helps us do it before and after the execution of the view function 1 Some extra operations
# For example:
#1.Django The project is enabled by default csrf Protection , Pass on each request CSRF Middleware checks whether there is a correct #token Value
#2. When the user sends a request on the page, through the user-defined authentication middleware, judge whether the user has logged in or not, and log in without logging in.
#3. When a user requests to come over, whether the user is in the white list or in the black list is judged 11. List five methods of django middleware?
#1.Django Take a big and comprehensive direction , High development efficiency. Its MTV Framework , Bring your own ORM,admin Background management , Bring your own sqlite Database and server for development test
# It improves the super high development efficiency for developers
#2.Flask Is a lightweight framework , Freedom , Flexible , Strong scalability , Core is based on Werkzeug WSGI Tools and jinja2 Template engine
#3.Tornado Going in the direction of less and more precision , Superior performance. It is best known for its asynchronous non-blocking design
#Tornado Two core modules of:
# 1.iostraem For non-blocking socket Simple encapsulation
# 2.ioloop : Right I/O Multiplexed encapsulation, which implements the 1 Singleton 12. When was the request object of django created?
#class WSGIHandler(base.BaseHandler):
# request = self.request_class(environ)
# Request to walk to WSGIHandler Class, execute the __cell__ Method, setting the environ Packaged into request13. How is Django redirection implemented? What status code is used?
#1. Use HttpResponseRedirect
#from django.http import HttpResponseRedirect
#2. Use redirect And reverse
# Status code: 301 And 302
#301 And 302 The difference:
# Same point: Both mean redirection, and the browser will automatically jump to the status code returned by the server 1 A new one URL Address
# Differences:
#301 A more common scenario is to use domain name jump. For example, we visit http://www.baidu.com Will jump to https://www.baidu.com
# Represents an old address A Has been permanently removed
#302 Used to make temporary jumps, such as unlogged users visiting the user center and redirecting to the login page. Represents an old address A The resource of is still there (still accessible), and this redirection is only temporarily from the old address A Jump to address B14. xxss Attack
#1.Django Take a big and comprehensive direction , High development efficiency. Its MTV Framework , Bring your own ORM,admin Background management , Bring your own sqlite Database and server for development test
# It improves the super high development efficiency for developers
#2.Flask Is a lightweight framework , Freedom , Flexible , Strong scalability , Core is based on Werkzeug WSGI Tools and jinja2 Template engine
#3.Tornado Going in the direction of less and more precision , Superior performance. It is best known for its asynchronous non-blocking design
#Tornado Two core modules of:
# 1.iostraem For non-blocking socket Simple encapsulation
# 2.ioloop : Right I/O Multiplexed encapsulation, which implements the 1 Singleton 15. Implementation mechanism of csrf in django
#1.Django Take a big and comprehensive direction , High development efficiency. Its MTV Framework , Bring your own ORM,admin Background management , Bring your own sqlite Database and server for development test
# It improves the super high development efficiency for developers
#2.Flask Is a lightweight framework , Freedom , Flexible , Strong scalability , Core is based on Werkzeug WSGI Tools and jinja2 Template engine
#3.Tornado Going in the direction of less and more precision , Superior performance. It is best known for its asynchronous non-blocking design
#Tornado Two core modules of:
# 1.iostraem For non-blocking socket Simple encapsulation
# 2.ioloop : Right I/O Multiplexed encapsulation, which implements the 1 Singleton 16. When sending post requests using ajax based on django, which method can be used to carry csrf token?
#1.Django Take a big and comprehensive direction , High development efficiency. Its MTV Framework , Bring your own ORM,admin Background management , Bring your own sqlite Database and server for development test
# It improves the super high development efficiency for developers
#2.Flask Is a lightweight framework , Freedom , Flexible , Strong scalability , Core is based on Werkzeug WSGI Tools and jinja2 Template engine
#3.Tornado Going in the direction of less and more precision , Superior performance. It is best known for its asynchronous non-blocking design
#Tornado Two core modules of:
# 1.iostraem For non-blocking socket Simple encapsulation
# 2.ioloop : Right I/O Multiplexed encapsulation, which implements the 1 Singleton 17. Django itself provides runserver, why can't it be deployed? (Difference between runserver and uWSGI)
#1.Django Take a big and comprehensive direction , High development efficiency. Its MTV Framework , Bring your own ORM,admin Background management , Bring your own sqlite Database and server for development test
# It improves the super high development efficiency for developers
#2.Flask Is a lightweight framework , Freedom , Flexible , Strong scalability , Core is based on Werkzeug WSGI Tools and jinja2 Template engine
#3.Tornado Going in the direction of less and more precision , Superior performance. It is best known for its asynchronous non-blocking design
#Tornado Two core modules of:
# 1.iostraem For non-blocking socket Simple encapsulation
# 2.ioloop : Right I/O Multiplexed encapsulation, which implements the 1 Singleton 18. Differences between cookie and session:
#1.Django Take a big and comprehensive direction , High development efficiency. Its MTV Framework , Bring your own ORM,admin Background management , Bring your own sqlite Database and server for development test
# It improves the super high development efficiency for developers
#2.Flask Is a lightweight framework , Freedom , Flexible , Strong scalability , Core is based on Werkzeug WSGI Tools and jinja2 Template engine
#3.Tornado Going in the direction of less and more precision , Superior performance. It is best known for its asynchronous non-blocking design
#Tornado Two core modules of:
# 1.iostraem For non-blocking socket Simple encapsulation
# 2.ioloop : Right I/O Multiplexed encapsulation, which implements the 1 Singleton 19. Enumerate all the methods in django orm (all the methods of the QuerySet object)
#1.Django Take a big and comprehensive direction , High development efficiency. Its MTV Framework , Bring your own ORM,admin Background management , Bring your own sqlite Database and server for development test
# It improves the super high development efficiency for developers
#2.Flask Is a lightweight framework , Freedom , Flexible , Strong scalability , Core is based on Werkzeug WSGI Tools and jinja2 Template engine
#3.Tornado Going in the direction of less and more precision , Superior performance. It is best known for its asynchronous non-blocking design
#Tornado Two core modules of:
# 1.iostraem For non-blocking socket Simple encapsulation
# 2.ioloop : Right I/O Multiplexed encapsulation, which implements the 1 Singleton 20. What is the difference between only and defer?
#1.Django Take a big and comprehensive direction , High development efficiency. Its MTV Framework , Bring your own ORM,admin Background management , Bring your own sqlite Database and server for development test
# It improves the super high development efficiency for developers
#2.Flask Is a lightweight framework , Freedom , Flexible , Strong scalability , Core is based on Werkzeug WSGI Tools and jinja2 Template engine
#3.Tornado Going in the direction of less and more precision , Superior performance. It is best known for its asynchronous non-blocking design
#Tornado Two core modules of:
# 1.iostraem For non-blocking socket Simple encapsulation
# 2.ioloop : Right I/O Multiplexed encapsulation, which implements the 1 Singleton 21. What is the difference between select_related and prefetch_related?
# When there are foreign keys, it can reduce the number of database requests , Improve performance
#select_related Through multiple tables join Association query ,1 Obtain all data in a secondary manner , Execute only 1 Times SQL Query
#prefetch_related Query each table separately , Then deal with it according to the relationship between them , Execute the query twice 22. What is the difference between filter and exclude?
# The values obtained are all QuerySet Object ,filter Select the that meets the conditions ,exclude: Exclude those that meet the conditions .23. What are the roles of F and Q?
#F: Operating on different fields of the data itself Such as : Compare and update
#Q Used to construct complex query conditions Such as: & | Operation 24. What is the difference between values and values_list?
#values : Dictionary's queryset
#values_list : Tuple-taking queryset25. How do I bulk create data using django orm?
#bulk_create()
#objs=[models.Book(title=" Books {}".format(i+15)) for i in range(100)]
#models.Book.objects.bulk_create(objs)26. The role of Form and ModeForm of django?
#Form Function:
# 1. Generate at the front end HTML Code
# 2. Check the validity of the data
# 3. Returns verification information and displays
#ModeForm Generate from model classes From Component , And can operate the database 27. In the Form component of django, if the field contains choices parameters, there are two ways to update the data source in real time.
#WSGI:
# web Server gateway interface , Yes 1 Set of agreements. Used to receive the user request, encapsulate the request for the first time, and then hand the request to the web Framework
# Realization wsgi Modules of the protocol:
# 1.wsgiref, Is essentially writing 1 A socket Server for receiving user requests (django)
# 2.werkzeug, Is essentially writing 1 A socket Server for receiving user requests (flask)
#uwsgi:
# And WSGI1 Sample is 1 A communication protocol, which is uWSGI Exclusive protocol of server , Used to define the type of information to be transmitted
#uWSGI:
# Yes 1 A web Server , Realized WSGI Agreement ,uWSGI Agreement ,http Agreement ,28. What is the effect of the on_delete parameter in the ForeignKey field in Model of django?
#WSGI:
# web Server gateway interface , Yes 1 Set of agreements. Used to receive the user request, encapsulate the request for the first time, and then hand the request to the web Framework
# Realization wsgi Modules of the protocol:
# 1.wsgiref, Is essentially writing 1 A socket Server for receiving user requests (django)
# 2.werkzeug, Is essentially writing 1 A socket Server for receiving user requests (flask)
#uwsgi:
# And WSGI1 Sample is 1 A communication protocol, which is uWSGI Exclusive protocol of server , Used to define the type of information to be transmitted
#uWSGI:
# Yes 1 A web Server , Realized WSGI Agreement ,uWSGI Agreement ,http Agreement ,29. How does django implement websocket?
#WSGI:
# web Server gateway interface , Yes 1 Set of agreements. Used to receive the user request, encapsulate the request for the first time, and then hand the request to the web Framework
# Realization wsgi Modules of the protocol:
# 1.wsgiref, Is essentially writing 1 A socket Server for receiving user requests (django)
# 2.werkzeug, Is essentially writing 1 A socket Server for receiving user requests (flask)
#uwsgi:
# And WSGI1 Sample is 1 A communication protocol, which is uWSGI Exclusive protocol of server , Used to define the type of information to be transmitted
#uWSGI:
# Yes 1 A web Server , Realized WSGI Agreement ,uWSGI Agreement ,http Agreement ,30. How do I set up read-write separation in django orm?
#WSGI:
# web Server gateway interface , Yes 1 Set of agreements. Used to receive the user request, encapsulate the request for the first time, and then hand the request to the web Framework
# Realization wsgi Modules of the protocol:
# 1.wsgiref, Is essentially writing 1 A socket Server for receiving user requests (django)
# 2.werkzeug, Is essentially writing 1 A socket Server for receiving user requests (flask)
#uwsgi:
# And WSGI1 Sample is 1 A communication protocol, which is uWSGI Exclusive protocol of server , Used to define the type of information to be transmitted
#uWSGI:
# Yes 1 A web Server , Realized WSGI Agreement ,uWSGI Agreement ,http Agreement ,31. How to create 1 log record when data is added to an orm table in django.
32. What is the built-in caching mechanism for django?
# Whole station cache
MIDDLEWARE_CLASSES = (
' django.middleware.cache.UpdateCacheMiddleware', # No. 1 1
'django.middleware.common.CommonMiddleware',
' django.middleware.cache.FetchFromCacheMiddleware', # Finally
)
# View cache
from django.views.decorators.cache import cache_page
import time
@cache_page(15) # The timeout time is 15 Seconds
def index(request):
t=time.time() # Get the current time
return render(request,"index.html",locals())
# Template cache
{% load cache %}
<h3 style="color: green"> Not caching :-----{{ t }}</h3>
{% cache 2 'name' %} # Saved key
<h3> Cache :-----:{{ t }}</h3>
{% endcache %}33. Can the cache of django use redis? If possible, how to configure it?
#1.wsgi, The request is encapsulated and handed to web Framework ( Flask , Django )
#2. Middleware, which validates the request or adds other relevant data to the request object, such as: csrf , request.session -
#3. Route matching Depending on what the browser sends url To match different view functions
#4. View function, in which business logic is processed, may involve: orm , templates => Render -
#5. Middleware, which processes the response data.
#6.wsgi, Sends the content of the response to the browser. 34. What is the difference between filter and simple_tag in the template of django?
#1.wsgi, The request is encapsulated and handed to web Framework ( Flask , Django )
#2. Middleware, which validates the request or adds other relevant data to the request object, such as: csrf , request.session -
#3. Route matching Depending on what the browser sends url To match different view functions
#4. View function, in which business logic is processed, may involve: orm , templates => Render -
#5. Middleware, which processes the response data.
#6.wsgi, Sends the content of the response to the browser. 35. The role of django-debug-toolbar?
#1.wsgi, The request is encapsulated and handed to web Framework ( Flask , Django )
#2. Middleware, which validates the request or adds other relevant data to the request object, such as: csrf , request.session -
#3. Route matching Depending on what the browser sends url To match different view functions
#4. View function, in which business logic is processed, may involve: orm , templates => Render -
#5. Middleware, which processes the response data.
#6.wsgi, Sends the content of the response to the browser. 36. How do you implement unit testing in django?
37. Explain the meaning of db first and code first in orm?
#1.wsgi, The request is encapsulated and handed to web Framework ( Flask , Django )
#2. Middleware, which validates the request or adds other relevant data to the request object, such as: csrf , request.session -
#3. Route matching Depending on what the browser sends url To match different view functions
#4. View function, in which business logic is processed, may involve: orm , templates => Render -
#5. Middleware, which processes the response data.
#6.wsgi, Sends the content of the response to the browser. 38. How do you generate classes in model from database tables in django?
#1.wsgi, The request is encapsulated and handed to web Framework ( Flask , Django )
#2. Middleware, which validates the request or adds other relevant data to the request object, such as: csrf , request.session -
#3. Route matching Depending on what the browser sends url To match different view functions
#4. View function, in which business logic is processed, may involve: orm , templates => Render -
#5. Middleware, which processes the response data.
#6.wsgi, Sends the content of the response to the browser. 39. What are the advantages and disadvantages of using orm and native sql?
#1.wsgi, The request is encapsulated and handed to web Framework ( Flask , Django )
#2. Middleware, which validates the request or adds other relevant data to the request object, such as: csrf , request.session -
#3. Route matching Depending on what the browser sends url To match different view functions
#4. View function, in which business logic is processed, may involve: orm , templates => Render -
#5. Middleware, which processes the response data.
#6.wsgi, Sends the content of the response to the browser. 40. What does the contenttype component of django do?
#1.wsgi, The request is encapsulated and handed to web Framework ( Flask , Django )
#2. Middleware, which validates the request or adds other relevant data to the request object, such as: csrf , request.session -
#3. Route matching Depending on what the browser sends url To match different view functions
#4. View function, in which business logic is processed, may involve: orm , templates => Render -
#5. Middleware, which processes the response data.
#6.wsgi, Sends the content of the response to the browser. 41. Talk about your understanding of restful specification?
#1.wsgi, The request is encapsulated and handed to web Framework ( Flask , Django )
#2. Middleware, which validates the request or adds other relevant data to the request object, such as: csrf , request.session -
#3. Route matching Depending on what the browser sends url To match different view functions
#4. View function, in which business logic is processed, may involve: orm , templates => Render -
#5. Middleware, which processes the response data.
#6.wsgi, Sends the content of the response to the browser. 42. What does the idempotence of an interface mean?
#1. Is the interface of the system 1 A kind of commitment ( Instead of realizing )
#2. Promise that as long as the interface is called successfully, , The impact of multiple external calls on the system is 1 To , Do not repeat operations on resources 43. What is RPC?
#FBV And CBV The essence is 1 Like
# Function-based views are called FBV The class-based view is called CBV
# In python Use in CBV Advantages of:
#1. Improve the reusability of code and use object-oriented technologies, such as Mixin (Multiple inheritance)
#2. You can use different functions for different HTTP Method, not through many if Judge and improve code readability 44. Why use API
#FBV And CBV The essence is 1 Like
# Function-based views are called FBV The class-based view is called CBV
# In python Use in CBV Advantages of:
#1. Improve the reusability of code and use object-oriented technologies, such as Mixin (Multiple inheritance)
#2. You can use different functions for different HTTP Method, not through many if Judge and improve code readability 45. Why use the django rest framework framework?
#FBV And CBV The essence is 1 Like
# Function-based views are called FBV The class-based view is called CBV
# In python Use in CBV Advantages of:
#1. Improve the reusability of code and use object-oriented technologies, such as Mixin (Multiple inheritance)
#2. You can use different functions for different HTTP Method, not through many if Judge and improve code readability 46. What are the components in the django rest framework framework?
#FBV And CBV The essence is 1 Like
# Function-based views are called FBV The class-based view is called CBV
# In python Use in CBV Advantages of:
#1. Improve the reusability of code and use object-oriented technologies, such as Mixin (Multiple inheritance)
#2. You can use different functions for different HTTP Method, not through many if Judge and improve code readability 47. What classes can views in the django rest framework framework inherit?
#FBV And CBV The essence is 1 Like
# Function-based views are called FBV The class-based view is called CBV
# In python Use in CBV Advantages of:
#1. Improve the reusability of code and use object-oriented technologies, such as Mixin (Multiple inheritance)
#2. You can use different functions for different HTTP Method, not through many if Judge and improve code readability 48. Briefly describe the authentication process of django rest framework framework
#FBV And CBV The essence is 1 Like
# Function-based views are called FBV The class-based view is called CBV
# In python Use in CBV Advantages of:
#1. Improve the reusability of code and use object-oriented technologies, such as Mixin (Multiple inheritance)
#2. You can use different functions for different HTTP Method, not through many if Judge and improve code readability 49. How does django rest framework realize user access frequency control
#FBV And CBV The essence is 1 Like
# Function-based views are called FBV The class-based view is called CBV
# In python Use in CBV Advantages of:
#1. Improve the reusability of code and use object-oriented technologies, such as Mixin (Multiple inheritance)
#2. You can use different functions for different HTTP Method, not through many if Judge and improve code readability 50. The role of the rest_framework serialization component, and some hook methods for foreign key relationships
#FBV And CBV The essence is 1 Like
# Function-based views are called FBV The class-based view is called CBV
# In python Use in CBV Advantages of:
#1. Improve the reusability of code and use object-oriented technologies, such as Mixin (Multiple inheritance)
#2. You can use different functions for different HTTP Method, not through many if Judge and improve code readability 51. What do you need to do in advance before providing users with an interface
#FBV And CBV The essence is 1 Like
# Function-based views are called FBV The class-based view is called CBV
# In python Use in CBV Advantages of:
#1. Improve the reusability of code and use object-oriented technologies, such as Mixin (Multiple inheritance)
#2. You can use different functions for different HTTP Method, not through many if Judge and improve code readability 52. PV and UV
#FBV And CBV The essence is 1 Like
# Function-based views are called FBV The class-based view is called CBV
# In python Use in CBV Advantages of:
#1. Improve the reusability of code and use object-oriented technologies, such as Mixin (Multiple inheritance)
#2. You can use different functions for different HTTP Method, not through many if Judge and improve code readability 53. What is cross-domain and the solution:
# Introduce method_decorator Module
#1. Adding a decorator directly to the class
#@method_decorator(test,name='dispatch')
#class Loginview(View):
# pass
#2. Add a decorator directly in front of the processed function
#@method_decorator(test)
# def post(self,request,*args,**kwargs):pass54. How to achieve user login authentication
# Introduce method_decorator Module
#1. Adding a decorator directly to the class
#@method_decorator(test,name='dispatch')
#class Loginview(View):
# pass
#2. Add a decorator directly in front of the processed function
#@method_decorator(test)
# def post(self,request,*args,**kwargs):pass55. How to convert dict to the format of url:
# Introduce method_decorator Module
#1. Adding a decorator directly to the class
#@method_decorator(test,name='dispatch')
#class Loginview(View):
# pass
#2. Add a decorator directly in front of the processed function
#@method_decorator(test)
# def post(self,request,*args,**kwargs):pass