RuntimeError: Working outside of application context in flask

In flask, Python is used to write microweb apps, and it does not require any libraries or tools. Flask also contains no database layer. A flask application is developed using the Werkzeug WSGI toolkit and the Jinja2 template engine. They are both Pocco projects.

It is possible that you will encounter this error when writing your first program in Flask.

This RuntimeError: working outside of application context in flask can be resolved pretty quickly.

Let's dive in:

This is how your compiler throws this error. It can be resolved if we understand how flask works.

Whenever Flask accesses some items from the Application Context, many of these are simple proxy settings that are already in the context of the Flask app.

Because of this, Flask throws a RuntimeError: working outside of application context

The Solution

from flask import Flask
app = Flask(__name__)
@app.route('/')
def Hola():
  return 'I am using flask'
if __name__ == '__main__':
  app.run()

Note: Before running flask code, make sure your Python version and IDE are compatible.

Further Reading

1. [SOLVED] psql: FATAL database 'root' does not exist error
2. [SOLVED] ValueError: View function did not return a response
3. What is Atatus APM and its Benefits?