Flask POSTs with Trailing Slash

Question

The documentation states that the preferred way to define a route is to include a trailing slash:

@app.route('/foo/', methods=['GET'])
def get_foo():
    pass

This way, a client can GET /foo or GET /foo/ and receive the same result.

However, POSTed methods do not have the same behavior.

from flask import Flask
app = Flask(__name__)

@app.route('/foo/', methods=['POST'])
def post_foo():
    return "bar"

app.run(port=5000)

Here, if you POST /foo, it will fail with method not allowed if you are not running in debug mode, or it will fail with the following notice if you are in debug mode:

A request was sent to this URL (http://localhost:5000/foo) but a redirect was issued automatically by the routing system to "http://localhost:5000/foo/". The URL was defined with a trailing slash so Flask will automatically redirect to the URL with the trailing slash if it was accessed without one. Make sure to directly send your POST-request to this URL since we can't make browsers or HTTP clients redirect with form data reliably or without user interaction

---

Moreover, it appears that you cannot even do this:

@app.route('/foo', methods=['POST'])
@app.route('/foo/', methods=['POST'])
def post_foo():
    return "bar"

Or this:

@app.route('/foo', methods=['POST'])
def post_foo_no_slash():
    return redirect(url_for('post_foo'), code=302)

@app.route('/foo/', methods=['POST'])
def post_foo():
    return "bar"

---

Is there any way to get POST to work on both non-trailing and trailing slashes?

Answer 1

Please refer to this post: Trailing slash triggers 404 in Flask path rule

You can disable strict slashes to support your needs

Globally:

app = Flask(__name__)
app.url_map.strict_slashes = False

... or per route

@app.route('/foo', methods=['POST'], strict_slashes=False)
def foo():
    return 'foo'

You can also check this link. There is separate discussion on github on this one. https://github.com/pallets/flask/issues/1783