G object for request-scoped data in Flask - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the g object in Flask?

The g object is used to store data during a single request. It helps share information between functions without using global variables.

beginner

How long does data stored in g last?

Data in g lasts only for the current request. It is cleared automatically after the request ends.

beginner

How do you store a value in the g object?

You assign a value like this: g.my_value = 42. This value can then be accessed anywhere during the request.

intermediate

Why is g preferred over global variables for request data?

Because g is unique to each request, it avoids conflicts and data leaks between users or requests, unlike global variables.

intermediate

Can you give an example use case for the g object?

A common use is to store a database connection during a request so multiple functions can use it without reopening connections.

What does the Flask g object store?

A Data for the current request only

B Global data shared across all requests

C User session data stored permanently

D Configuration settings for the app

The g object stores data only for the current request, not globally or permanently.

How do you access the g object in Flask?

A Use <code>request.g</code>

B Import it from flask and use it directly

C Use <code>session.g</code>

D It is a global variable without import

You import g from Flask with from flask import g and then use it.

What happens to data stored in g after the request ends?

A It is saved to a file

B It is sent to the client

C It persists for the next request

D It is cleared automatically

Data in g is cleared automatically after the request finishes.

Which of these is a good use for g?

A Storing app configuration

B Saving user login info permanently

C Storing a database connection for the request

D Keeping global counters

g is ideal for request-specific data like a database connection.

Why avoid using global variables instead of g for request data?

A Global variables can cause data conflicts between requests

B Global variables are faster

C Global variables are cleared after each request

D Global variables are only for configuration

Global variables can mix data between requests, causing bugs. g keeps data separate per request.

Explain what the Flask g object is and why it is useful.

Think about how to share info safely during one web request.

Describe a practical example of using the g object in a Flask app.

Consider resources that need to be reused during one request.