how to redirect to a external 404 page python flask

Question

I am trying to redirect my 404 to a external URL like this:

@app.route('404')
def http_error_handler(error):
    return flask.redirect("http://www.exemple.com/404"), 404

but it does not work. I keep getting:

Not Found The requested URL was not found on the server. If you entered the URL manually please check your spelling and try again.

Solution 1

You should try something like this:

from flask import render_template

@app.errorhandler(404)
def page_not_found(e):
    return render_template('404.html'), 404

Source http://flask.pocoo.org/docs/1.0/patterns/errorpages/

Solution 2

Try this instead of a route

from flask import request
@app.errorhandler(404)
def own_404_page(error):
    pageName =  request.args.get('url')
    print(pageName)
    print(error)
    f = open('erreur404.tpl')
    return f.read()

Solution 3

You cannot do this - the user-agent (in most cases, a browser) looks at the status code that is returned to determine what to do. When you return a 404 status code what you are saying to the user-agent is, "I don't know what this thing is you are requesting" and the user-agent can then:

• Display what you return in the body of the response
• Display its own error message to the end user
• Do some combination of the above two options

redirect actually creates a little HTML response (via werkzeug.exceptions), which normally the end user doesn't see because the user-agent follows the Location header when it sees the 302 response. However, you override the status code when you provide your own status code (404).

The fix is to either:

• Remove the status code (at the cost of sending the wrong signal to the end user, potentially)

• or Send a 404 with a meta:refresh and / or JavaScript redirect (slightly better, still confusing):

  return redirect("/where-ever"), 404, {"Refresh": "1; url=/where-ever"}
  

Comments

[Phosy]

I don't have the 404.html file on the same project I need to redirect to another website and still have my 404 status code I already look at the doc many times..

[lapinkoira]

Well you dont have to actually redirect to a template, do something like this return redirect("example.com", code=302)

[lapinkoira]

It just an example to show how to handle the error, then inside you do whatever you want

[lapinkoira]

Dude, just type 404, it's an example, what do u want, to just copy and paste?

[lapinkoira]

So you are handing the 404 error but when should be redirected to exemple.com/404 you are getting this error instead? "Not Found The requested URL", like, some 500 internal server error?

[Phosy]

I'm getting this I already try this "Redirecting... You should be redirected automatically to target URL: exemple.com/404. If not click the link." but it never redirect ....

[Jamie Lindsey]

Whats actually hilarious is that now (2019), the link above return an actual 404 error page, hehe! the new link link is flask.pocoo.org/docs/1.0/patterns/errorpages

[Jamie Lindsey]

Nearly every line in your example is very non-pythonic. You suggest to use CamelCase in place of snake_case, your reading a file template instead of return a response, and pointlessly printing the page name. Just my opinion.

[Coder]

what is request?

[Quentin]

@JohnD probably found out by now but that's referring to flask.request