python -c 'import secrets; print(secrets.token_hex())''192b9bdd22ab9ed4d12e236c78afcb9a393ec15f71bbf5dc987d54727823bcbf' Delete the original app.py file in the project root, as its contents have been moved into other app files. Copy that line into the > prompt at the bottom of the debug console, and try changing the formatting: now.strftime( "%a, %d %B, %Y at %X" ) 'Wed, 31 October, 2018 at 18:13:39' now.strftime( "%a, %d %b, %Y at %X" ) 'Wed, 31 Oct, 2018 at 18:13:39' now.strftime( "%a, %d %b, %y at %X" ) 'Wed, 31 Oct, 18 at 18:13:39' Flask can be used with any database like:- SQL and NoSQL and with any Frontend Technology such as React or Angular.

The global request object to access incoming request data that will be submitted via the HTML form you built in the last step. Now that you have a SQL schema in the schema.sql file, you’ll use it to create the database using a Python file that will generate an SQLite .db database file. Open a file named init_db.py inside the flask_blog directory using your preferred editor: For example, in a simple blog that has content URLs organized by year, month, and day published, the URL “posts/2021/09/01” would retrieve the blog post published on September 1, 2021. Similarly, the URL “posts/2021/09” would retrieve an archive with links to all posts published in September, while the URL “posts/2021” would do the same for the entirety of 2021. app . route ( "/me" ) def me_api (): user = get_current_user () return { "username" : user . username , "theme" : user . theme , "image" : url_for ( "user_image" , filename = user . image ), } @app . route ( "/users" ) def users_api (): users = get_all_users () return [ user . to_json () for user in users ] the application secure. Because of that Flask configures the Jinja2 template engine for you automatically.

Next, create a templates folder in your flask_app directory where Flask searches for templates, then open a template file called base.html, which will have code that other templates will inherit to avoid code repetition:

from flask import make_response @app . errorhandler ( 404 ) def not_found ( error ): resp = make_response ( render_template ( 'error.html' ), 404 ) resp . headers [ 'X-Something' ] = 'A value' return resp APIs with JSON ¶ Read on to learn more about Flask and Django, or use the table of contents below to jump to a specific section. This series is designed to help developers answer that question by comparing those four frameworks. To compare their features and operations, I'll take each one through the process of constructing an API for a simple To-Do List web application. The API is itself fairly straightforward:In the Integrated Terminal, run the app by entering python -m flask run, which runs the Flask development server. The development server looks for app.py by default. When you run Flask, you should see output similar to the following: (.venv) D: \p y \\ hello_flask>python -m flask run * Environment: production WARNING: Do not use the development server in a production environment. Use a production WSGI server instead. * Debug mode: off * Running on http://127.0.0.1:5000/ (Press CTRL+C to quit) Once your programming environment is activated, your prompt will now have an env prefix that may look as follows: head > Whenever data is sent to the application, regardless of the HTTP method used, that data is stored on the form attribute of the request object. The name of the field on the frontend will be the name of the key mapped to that data in the form dictionary. It'll always come in the form of a string, so if you want your data to be a specific data type, you'll have to make it explicit by casting it as the appropriate type. A good way to get moving is to turn the codebase into an installable Python distribution. At the project's root, create setup.py and a directory called todo to hold the source code.

On top of that it’s very explicit, which increases readability. To create the “Hello World” app, you only need a few lines of code. For the "one," set a field for the tasks the specific user owns. Similar to maintaining the two-way relationship on the Task object, set a keyword argument on the User's relationship field to update the Task when it is assigned to a user. # on the Task objectTo communicate with the database within a view, you must use the db object that was populated toward the top of the script. Its session attribute is your connection to the database when you want to make changes. If you just want to query for objects, the objects built from db.Model have their own database interaction layer through the query attribute. Python libraries are collections of functions and methods that must be explicitly called by the developer. They’re designed and organized to solve specific types of problems. For example, you could use a Python library for:

In this case, you're building a To-Do List with Tasks, and each Task belongs to a User. Before you think too deeply about how they're related to each other, start by defining objects for Tasks and Users. In the templates folder, create a file named hello_there.html with the contents below. This template contains two placeholders named "name" and "date", which are delineated by pairs of curly braces, {{ and }}. As you can see, you can also include formatting code in the template directly: {%if name %} Hello there, {{ name }}! It's {{ date.strftime("%A, %d %B, %Y at %X") }}. {% else %} What's your name? Provide it after /hello/ in the URL. {% endif %} To solve this problem, either stop the server that’s currently running via CTRL+C, then run flask run again, or if you want to run both at the same time, you can pass a different port number to the -p argument, for example, to run another application on port 5001 use the following command: Also in app.py, modify the hello_there function to use render_template to load a template and apply the named values (and add a route to recognize the case without a name). render_template assumes that the first argument is relative to the templates folder. Typically, developers name the templates the same as the functions that use them, but matching names are not required because you always refer to the exact filename in your code. @app.route ( "/hello/" ) @app.route ( "/hello/" ) def hello_there ( name = None ): return render_template( "hello_there.html" , name =name, date =datetime.now() )Move the static and templates folders into hello_app, because these folders certainly contain app code. While people often associate Python with data science and analysis, it can also be a helpful tool for creating powerful web applications. In fact, you may have already heard of Flask and Django — two Python frameworks used to develop web apps.