How do you get a query string on Flask?

Question

Not obvious from the flask documention on how to get the query string. I am new, looked at the docs, could not find!

So

@app.route('/')
@app.route('/data')
def data():
    query_string=??????
    return render_template("data.html")

Answer 1

The full URL is available as request.url, and the query string is available as request.query_string.

Here's an example:

from flask import request

@app.route('/adhoc_test/')
def adhoc_test():

    return request.query_string

To access an individual known param passed in the query string, you can use request.args.get('param'). This is the "right" way to do it, as far as I know.

ETA: Before you go further, you should ask yourself why you want the query string. I've never had to pull in the raw string - Flask has mechanisms for accessing it in an abstracted way. You should use those unless you have a compelling reason not to.

Answer 2

from flask import request

@app.route('/data')
def data():
    # here we want to get the value of user (i.e. ?user=some-value)
    user = request.args.get('user')

Answer 3

We can do this by using request.query_string.

Example:

Lets consider view.py

from my_script import get_url_params

@app.route('/web_url/', methods=('get', 'post'))
def get_url_params_index():
    return Response(get_url_params())

You also make it more modular by using Flask Blueprints - http://flask.pocoo.org/docs/0.10/blueprints/

Lets consider first name is being passed as a part of query string /web_url/?first_name=john

## here is my_script.py

## import required flask packages
from flask import request
def get_url_params():
    ## you might further need to format the URL params through escape.    
    firstName = request.args.get('first_name') 
    return firstName

As you see this is just a small example - you can fetch multiple values + formate those and use it or pass it onto the template file.

Answer 4

Werkzeug/Flask as already parsed everything for you. No need to do the same work again with urlparse:

from flask import request

@app.route('/')
@app.route('/data')
def data():
    query_string = request.query_string  ## There is it
    return render_template("data.html")

The full documentation for the request and response objects is in Werkzeug: http://werkzeug.pocoo.org/docs/wrappers/