Accessing query parameters in Flask - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a query parameter in a URL?

A query parameter is a key-value pair added to the end of a URL after a question mark (?). It is used to send extra information to the server, like filters or options.

beginner

How do you access query parameters in a Flask route?

You use request.args to get query parameters in Flask. It works like a dictionary where keys are parameter names and values are parameter values.

beginner

What does request.args.get('name') do in Flask?

It retrieves the value of the query parameter named 'name'. If 'name' is not in the URL, it returns None by default.

intermediate

How can you provide a default value when accessing a query parameter in Flask?

Use request.args.get('param', default='value'). If 'param' is missing, it returns the default value instead of None.

intermediate

What type of object is request.args in Flask?

request.args is an ImmutableMultiDict. It behaves like a dictionary but can hold multiple values for the same key and cannot be changed.

In Flask, which object holds the query parameters from a URL?

A request.data

B request.form

C request.args

D request.json

request.args contains the query parameters sent in the URL after the question mark.

What will request.args.get('page', '1') return if the URL has no 'page' parameter?

A 1

B None

C An error

D Empty string

The second argument to get is the default value returned if the parameter is missing.

If the URL is /search?term=flask&term=python, what type of object is request.args.getlist('term')?

A A string with both terms joined

B None

C A dictionary

D A list of strings ['flask', 'python']

getlist returns all values for a key as a list.

Which symbol separates query parameters from the main URL?

A ?

B &

C #

D /

The question mark ? starts the query string in a URL.

What happens if you try to modify request.args directly?

A It updates the query parameters

B It raises an error because it's immutable

C It silently ignores changes

D It converts to a list

request.args is immutable and cannot be changed directly.

Explain how to access and use query parameters in a Flask route.

Think about how URLs send extra info and how Flask reads it.

Describe the difference between request.args and request.form in Flask.

Consider where the data comes from in each case.