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Django Security middleware

What is middleware? Middleware is a program that acts as a bridge between two services/programs. Middleware should be like a plugin in any Framework. Middleware in  Django Middleware is a framework of hooks into Django’s request/response processing. Django supports both Custom and Built-in Middleware. This blog is

Your Guide to using Anaconda

If you're a data scientist or a Python developer or just starting out in the field, you'll likely need a Python distribution like Anaconda. It's one of the most popular Python distributions out there, and it includes pretty much everything you need to get

How to transfer files from EC2 to your local without ssh?

One of the most common situations while working with remote servers is to transfer huge files from the remote server to our local machine for better debugging. We all have gone through the issue where you cannot directly ssh into the remote machine, i.e. you have some kind of

Beware of Cross-site scripting (XSS) in Django Templates

1. Django Templates support Automatic HTML escaping. 2. Caveates in Django Templates leading to Cross-site scripting (XSS). 2.1 Safe Filter, 2.2 Unquoted Payload, 2.3 autoescape off 2.4 Variable in script tag

How to add a default 404 error page in Django?

404 is one of the most common errors for web applications to throw. But it is important to make sure that the end-user is not left hanging after a 404 error occurs, i.e. having no CTA (call to action) button available to the end-user. In the below example the

Show Output of shell command in realtime

Python is a very powerful language that is used for automation. And a lot of times we create CLI tools using python. Python can be used to write a wrapper that would call Unix commands and we want to also see the output of those commands. Let us see how

How to query reverse foreign key relationship in Django queryset?

TL;DR class Post(models.Model): content = models.TextField() class Comment(models.Model): comment_content = models.TextField() post = models.ForeignKey(Post, on_delete=models.CASCADE, related_name='comments_rel') created_at = models.DateTimeField(auto_add_now=True) # get all comments for a given post created in last 1

How to use a different delimiter for Python Template?

Python template is a super powerful feature that can help you to fill the placeholders on the fly. But by default, the delimiter used by python for the template is a dollar $ , though this is perfect, at times you might need to use dollar in your final string and that

How to fix any Django Migration issue in local?

Let us resolve any Django migration issue locally. Let us say you added a new field into the models.py file which caused the migration failure. The reason for migration failure can be anything, maybe a bad state of the database, or failure of old migration command, etc. I would

How to add custom security groups to beanstalk?

.ebextensions can help you attach custom security groups to the instance. * Create a new security group, make sure to name the security group appropriately. You can add your custom inbound and outbound rules to the configuration. Let us name it demo-security-group, make sure to use the Security Group Name and

How to open SailJS console in terminal?

The biggest advantage of interpreter language is the use of a console. Be it Python or NodeJS, a developer can quickly open the shell and see execute snippets of the code. Once you start using the framework, suddenly the comfort of using a console goes away if the framework doesn&

How to render content with Context using Template in Django?

Django template is a powerful built-in feature that most people on the modern web tend to overlook. Even I have myself overlooked this feature for more than 3 years into Django development, to finally embrace it with open arms. Let us first try to see how to renderContext using Template

Why should you learn docker?

Gone are those days when you could be an expert of a certain language/framework and survive as a developer in the Industry. In today's fast-moving tech world, you are expected to be a problem solver. Companies want people who can understand the business problem and build a

How to work with multiple NodeJS versions using fnm?

Working with multiple NodeJS projects can be challenging at times with different NodeJS version requirements. There are multiple tools that can help with working with multiple versions like * nvm [https://github.com/nvm-sh/nvm] * n [https://github.com/tj/n] * fnm [https://github.com/Schniz/fnm] (My go-to approach which

How to add a comment feature to Ghost blogs?

Comment is one of the most engaging feature for any blog. Ghost is one of the best blogging platforms with a great user experience, but unfortunately, it doesn't support any comment support out of the box. Though there are a few options that Ghost suggests they are mostly

How to upgrade all packages in JS or NodeJS?

Javascript ecosystem is one of the finest and most evolving platform in the programming community. Hence you would find a lot of times the packages you have used in your project or in the global space get outdated soon. It becomes a task to then go and find out the

How to configure flake8 in Django?

Code formatting and hygiene is one of the most crucial aspects of a project, this determines if all your fellow developers love to work on the codebase or they have a frustration look when a new task is given to them. How much so ever the senior folks in the

How to make https POST request using native https package in nodejs?

Native packages are one of the most performance oriented way to perform any task. While working with NodeJS one would encounter the most common task of making an HTTP request. There are multiple built-in packages and also third-party packages which can be used to do the same. * Native https [https:

Cloudfront IP address list for all locations

Using CDN would be one of the first pieces of advice which anyone would give when you want to improve the performance of your globally distributed users. CloudFront is the AWS CDN, which helps you integrate seamlessly into the AWS ecosystem. While using CloudFront you might come across one of

How to protect your cookie from getting accessed by malicious client scripts using HttpOnly

A cookie can be accessed through javascript if it does not have the HttpOnly header set. An attacker who managed to perform XSS or run a client-side script is able to access the cookie if it does not have the HttpOnly flag set. Cookie with HttpOnly flag set is inaccessible

How to implement and test your Content Security Policy (CSP)

> Never let browser blindly trust any source of the content received from the server. Allowing all data sources by a web application can lead to execution of malicious scripts. Hence it is important to add a additional defence layer to mitigate and detect XSS, clickjacking and other code injection

Why does S3 take more time to upload after a few months of heavy usage?

The TLDR answer: If you are using a flat structure(i.e. no directory inside bucket) to upload objects to the S3 bucket, then there you go that is the answer. I have worked with buckets that have 2M objects but in a flat structure taking almost 5x the time

What is __call__ in Python?

Python exposes a lot of built-in methods which can help us override almost any operation with the objects. One of those methods is __call__ method. If we define a __call__ method then, it allows us to use the instance as a function. class Demo: def __init__(self): print('instantiated

How to remove/replace multiple occurrences of a particular word from a string?

Find and replace is one of the most common use cases in IDE, but while writing code we would also come across use cases when we want to replace or remove a given set of characters from a string. JavaScript is a bit notorious in this regard, it can be

How to configure 301 redirect in Ghost CMS?

When you start writing blogs on the Ghost CMS, you won't recognize that the URL for your blog gets picked up when you write the title for the first time, i.e. when you updated the title then the URL is not updated. This is a huge problem,

How to send logs from Django to NewRelic?

Logs are one of the most important tools used to debug or get info on whether your systems are working on the track. Adding logs to a system is pretty easy, and especially if you are using Django, you can take advantage of the built-in logging framework. But the difficult

How to google like a pro developer?

Googling is one of the most underrated skills which experienced developers possess. Believe it or not, whether a coder is starting their career or 10 years into their career, they will always end up googling something or the other thing for their daily job. Let us now see quick tips

How to perform healthcheck of Celery beat?

> Unpredictability or manual validation is the worst enemy of a developer. When we deploy any application to production our first hunch is to check if everything is working as expected. We start adding automatic health-check for all the systems in place so that we don't have to

How to reload Django shell without restarting?

Django shell is perhaps the first place where developers test their code and verify all the functionality. But we generally don't develop the whole code in the shell. most of the time we copy-paste the whole function and execute. Though this way of development is perfect for say

How to setup Celery with Django?

Celery is an asynchronous task framework that can be used to perform long-running jobs required in the Django web application

How to integrate Sentry for Django and Celery?

All developers want to write bug-free code and ship it to production. While developing on local we have stack trace to capture our errors and resolve them, but we don't have that privilege on a production server, then ultimately our end users will start experiencing bugs and we

How to add User IP address to NewRelic transaction for Django?

NewRelic out of the box would ignore collecting User IP, due to privacy concerns. But for a lot of web applications, it is important to capture user IP so that performance can be monitored by categorizing by different physical user IPs. To pass user IP to a transaction of the

How to integrate New Relic (APM) to Django?

Application Performance Monitoring (APM) is a must-have tool for any of the applications which are live for external users. I prefer using NewRelic as an APM for all of my applications. Before jumping into the installation please create a new account with NewRelic. Deliver more perfect softwareWork smarter and solve

How to create custom middleware in Django?

The TLDR answer: * Create a file custom_middleware.py file in the same folder as where Django settings.py file is present * Add the following code in custom_middleware.py class CustomMiddleware: def __init__(self, get_response): self.get_response = get_response def __call__(self, request): print("custom middleware

How to ignore certain endpoints in NewRelic APM in Django?

The best way to ignore certain endpoints/api from NewRelic APM would be to tweak the NewRelic agent flag using a middleware from newrelic import agent class CustomMiddleware: def __init__(self, get_response): self.get_response = get_response def __call__(self, request): # Check if the current url needs to be

How to setup health check for Django projects in production?

Once you have developed a web application, you would want to make sure that your service is up 24 x 7 and if for some reason the server goes down, then you would be notified. Here comes the use case of health checks for your website. If your application is

How to open links in New Tab in Ghost CMS

The TLDR answer You know how important it is for your blog to keep users in your domain rather than sending to some other website, but still, there would be scenarios where you have to add links to other domains and your users will click those links. By default Ghost

Top tools to improve your product life cycle

When we are starting our career we feel learning to code is the most difficult part, with time we realize that writing code is the easiest part, but building scalable reliable systems is the toughest. I tell this to folks looking for advice, anyone can write code but the most

Learnings after using Django for 5 years

The TLDR answer: * Even after 15 years, it is one of the best Frameworks in the market which can handle everything from rapid prototyping to a million request scale. * Truly stand by the motto - "The web framework for perfectionists with deadlines." * Best documentation when it comes to

When to use update_or_create in Django?

The TLDR answer: If you have used get_or_create [https://thetldr.tech/how-to-use-get-or-create-in-django/] you must have had the thought of if there is any Django ORM that could update_or_create. Well, Django has the exact implementation which can either update the DB object if present, else it would

How to check Django version?

Django has built-in util that gives you the current Django version, get_version which I would suggest you use. But apart from that method, you can use any of the following commands from the python shell, where you have to install Django. >>> import django >>>

How to use get_or_create in Django?

The TLDR answer This is one of those two query one command ORM methods. It would make a query to the database with the given where clause query and if not found then it will create a new entry in the table using the default values. It returns a tuple

Python top interview questions 2022

After working with python for so many years in the industry, I have curated a list of python interview questions for both freshers who are starting their careers and also for experienced developers who are applying for a senior position. I have tried to mark all my questions with relevant

Array vs List in Python

The array is a vector containing homogeneous elements, i.e same data types. All the elements are saved in continuous memory location so it has a better performance to lists in python. One important thing here we have to remember is that while creating an array we have to import

GIT for dummies

If you are starting with git it is highly possible to be overwhelmed by all the commands you have to remember to work. I won't be explaining how you can install git and what is the need for git, rather jump into the commands which you need to

What is the difference between blank and null in Django?

null=True would tell the underlying database that this field is allowed to save null. blank=True is applicable in the Django forms layer, i.e. any user is allowed to keep empty this field in Django form or Admin page. blank value is stored in the database.

How to get an emoji domain for your website?

Couple of years back I saw a weird domain printed on a marketing leaflet, it had emoji in the domain. The first impression I had– > Such a blunder, how could the team not check the domain name before printing the leaflets and also now they are distributing it . After

Django Top Interview Questions 2022

After working with Django for 5+ years and taking numerous interviews, I have realised that the questions one can ask in Django Interview are very limited. I have been on both sides of the table and to be honest, there are just a handful number of questions that one can

CURL for dummies

After being in the industry for so many years, I always felt that the power of curl is something which was unexplored by me. Most of the time I end up using Postman. Though Postman is a great tool with all the curl features implemented, but there are few scenarios

Linux Commands which we use daily

Ask any developer, and you will hear the same, switch your OS to Linux/Unix-based platform and switch to a terminal to have a better coding experience. But what we all forget is to share how daunting the whole migration strategy was for most of us. I started using the

How to create Django admin with readonly permission for all users?

The TLDR answer: We all have encounter situations when someone from the product team asks us to create a model dashboard. With Django admin page, this is just a few lines of code. But what about those scenarios when someone asks for access to a crucial table in the admin

What is the select query equivalent in PyMongo/MongoDB native query?

The TLDR answer: Coming from the SQL domain, you might stumble upon requirement of writing a select <field_1>, <field_2> from xyz in Mongodb. It might be a little tempting to not use select query, but try to avoid doing it, since it might be

How to update multiple fields in Django model efficiently?

The TLDR answer: The first answer which you would get when you search django model update on google you would find the .update() Django ORM. While this is great, let us see few points about .update() queryset - * post_save, pre_save signals does not get triggered. While this might

How to use Base Model (Inheritance) in Django?

The TLDR answer: Once you start creating a serious project in Django you would want to add created_at and updated_at to most of the models. That's when you realise you are not following the Don't Repeat Yourself(DRY) principle by copy-pasting the same field

How to disable delete option in Django admin?

The TL;DR answer: You need to add a new method has_delete_permission in the Admin class where you want to disable the delete function. from django.contrib import admin class OrganisationAdmin(admin.ModelAdmin): list_display = ("name", "id", "is_active", "domain_name&

How to explore Github repo in VS code?

The TLDR answer: Though I am not a VS code user, but at times I have been tempted to give it a shot to VS code. Recently I came across something in VS Code which has changed everything for me. I have decided switch to VS code for next 1

How to create a file using shell script (heredoc)?

The TLDR answer: If you need to use a shell script which would create a file with the dynamic content using few variables then you can use the code below. The approach we shall take here will use heredoc [https://en.wikipedia.org/wiki/Here_document] / here document syntax. cat

How to pass environment variable to Create React App (CRA) ?

The TLDR Answer: You need to start the variable name with REACT_APP_ . From the official documentation, you can read more [https://create-react-app.dev/docs/adding-custom-environment-variables/]. > Your project can consume variables declared in your environment as if they were declared locally in your JS files. By default you will

How to get a free domain for lifetime?

Freenom can be used to purchase any domain for free. The TDL(Top Domain Level) which freenom allows are tk, ga, ml, cf, gq. You can get the domain free for lifetime.

How to access member-only Medium stories for free forever?

The TLDR answer: I know this is not a tech-related question which you would stumble upon, but I believe, if you are a coder then definitely you read a lot of blogs in medium and a lot of them are members only. Most of the time we would open it

How to get IP address in Angular, React, VueJS, frontend Framework?

The TLDR answer: Using a third-party service is the best option possible according to me. One service which I have been using for years is https://jsonip.com. It hasn't let me down until now. Here are the code snippets you can use as per your framework: // If

How to check MongoDB ObjectId valid in JS?

The TLDR answer: If you are using mongoose [https://mongoosejs.com/docs/] as your ORM layer for MongoDB in any of the NodeJS frameworks then one of the simplest and best ways I have come across is if (!mongoose.Types.ObjectId.isValid(object_id)) { throw "Invalid id"; }

How to add Custom signals dispatch in Django?

Django provides a lot of features out of the box and all of them are production ready and battle tested. But one of the most underrated out of the box features which Django provides is Django signals.

How to setup periodic task in Celery, Django?

The TLDR answer: If you using celery for years, then you must have got used to the @periodic_task decorator to help you set up any periodic task. But as soon as you update your celery, you get a deprecation warning, or else if you start using the latest version

How to use better code snippet in Ghost Blog platform?

The TDLR answer : If you are using the Ghost platform for blogging, chances are you are a coder and write most of your blogs around coding. Though the interface and themes of ghost are configurable if you are someone like me who doesn't want to invest too much

How to configure Webstorm for docker container node_modules?

The TLDR answer: The path inside the container has to be /opt/project (exact path) where you are loading the project file and also installing the node_modules. Unfortunately, it is not well documented, and also no way to update the path as of now. The Detailed Answer: If you

How to connect different services between two different docker compose?

The TLDR answer: Since you are in two different docker-compose services, you can't use localhost neither you can use the service name. One way is to try using the host machine IP but I have faced issues multiple times. The safest option which has always worked for me

How to implement pagination in Django queryset using limit and offset?

The TLDR answer: Django utilizes the array slicing syntax of python to implement limit offset. For pagination in Django models, you need to use limit offset. Suppose you have 20 rows in a queryset and you want to access the data in batches of 5. first_five_rows = DBModel.objects.

How to write a scrapper/parser using Postman?

This blog shows how we can use Postman test script to write a scrapper/ parser using cheerio. Test scripts are executed on server side and not on the webapp/electron powered desktop app, which means you don't need to use your system or a separate server to run the parser.