How do I get the different parts of a Flask request's url?

Question

I want to detect if the request came from the localhost:5000 or foo.herokuapp.com host and what path was requested. How do I get this information about a Flask request?

Solution 1

You can examine the url through several Request fields:

Imagine your application is listening on the following application root:

http://www.example.com/myapplication

And a user requests the following URI:

http://www.example.com/myapplication/foo/page.html?x=y

In this case the values of the above mentioned attributes would be the following:

    path             /foo/page.html
    full_path        /foo/page.html?x=y
    script_root      /myapplication
    base_url         http://www.example.com/myapplication/foo/page.html
    url              http://www.example.com/myapplication/foo/page.html?x=y
    url_root         http://www.example.com/myapplication/

You can easily extract the host part with the appropriate splits.

Solution 2

another example:

request:

curl -XGET http://127.0.0.1:5000/alert/dingding/test?x=y

then:

request.method:              GET
request.url:                 http://127.0.0.1:5000/alert/dingding/test?x=y
request.base_url:            http://127.0.0.1:5000/alert/dingding/test
request.url_charset:         utf-8
request.url_root:            http://127.0.0.1:5000/
str(request.url_rule):       /alert/dingding/test
request.host_url:            http://127.0.0.1:5000/
request.host:                127.0.0.1:5000
request.script_root:
request.path:                /alert/dingding/test
request.full_path:           /alert/dingding/test?x=y

request.args:                ImmutableMultiDict([('x', 'y')])
request.args.get('x'):       y

Solution 3

you should try:

request.url 

It suppose to work always, even on localhost (just did it).

Solution 4

If you are using Python, I would suggest by exploring the request object:

dir(request)

Since the object support the method dict:

request.__dict__

It can be printed or saved. I use it to log 404 codes in Flask:

@app.errorhandler(404)
def not_found(e):
    with open("./404.csv", "a") as f:
        f.write(f'{datetime.datetime.now()},{request.__dict__}\n')
    return send_file('static/images/Darknet-404-Page-Concept.png', mimetype='image/png')

View more solutions

Comments

[Vadim]

I am trying to get Request.root_url and as return I get only <werkzeug.utils.cached_property object> instead of nicely formatted http://www.example.com/myapplication/. Or this feature does not work on localhost?

[selfboot]

@Vadim You should use request.root_url, not Request.root_url.

[Ulysse BN]

new to Flask, i didn’t know where request object come from and how it works, here it is: flask.pocoo.org/docs/0.12/reqcontext

[zerocog]

request.url_root works for me, whereas request.root_url and Request.root_url fail. Therefore, watch for the cap 'R' and url_root versus root_url

[moto]

url_root returns http://www.example.com/ not http://www.example.com/myapplication/ base_url returns http://www.example.com/myapplication/

[pfabri]

This should be the accepted answer, as it has a lot more detail to it.

[Tao Starbow]

This is a great answer. Very useful and complete.

[user4772933]

my app route is like @app.route('/index/<int:id1>/<int:id2>') how can i guest path from request without variables. I expect /index in result. Which flask function to use?

[Peilonrayz]

@Ian Request is a class where you interact with them through request which is an instance. This answer doesn't talk about the instance only the class. Leaving one to wonder "how I getz instance?"

[booshong]

@Peilonrayz that's a good point! The answer could be more explicit with how to use/reference those fields, though arguably the linked documentation helps with that. (and to be super pedantic, request is actually a proxy). But you're right; For the average user an explicit reference to plain request.path etc would be easier to digest.

[AnnieFromTaiwan]

For people who want to use request.full_path, suggest to use request.environ['RAW_URI'] instead. Because, when the actual full query path is /alert/dingding/test, request.full_path returns /alert/dingding/test?, an extra question mark will be added to the result, which might not be desirable.

[Abhay Bh]

Thanks! This detailed information helped a lot. Really appreciated.

[Anonymous12332313]

This is a great and very detailed answer

[PYK]

request.remote_addr for 127.0.0.1