Can Flask have optional URL parameters?

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Chapters
00:00 Can Flask Have Optional Url Parameters?
00:22 Accepted Answer Score 491
00:41 Answer 2 Score 247
00:58 Answer 3 Score 90
01:14 Answer 4 Score 36
01:23 Thank you

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Full question
https://stackoverflow.com/questions/1403...

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Content licensed under CC BY-SA
https://meta.stackexchange.com/help/lice...

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Tags
#python #flask

#avk47

ACCEPTED ANSWER

Score 491

Another way is to write

@user.route('/<user_id>', defaults={'username': None})
@user.route('/<user_id>/<username>')
def show(user_id, username):
    pass

But I guess that you want to write a single route and mark username as optional? If that's the case, I don't think it's possible.

ANSWER 2

Score 247

Almost the same as Audrius cooked up some months ago, but you might find it a bit more readable with the defaults in the function head - the way you are used to with python:

@app.route('/<user_id>')
@app.route('/<user_id>/<username>')
def show(user_id, username='Anonymous'):
    return user_id + ':' + username

ANSWER 3

Score 90

If you are using Flask-Restful like me, it is also possible this way:

api.add_resource(UserAPI, '/<userId>', '/<userId>/<username>', endpoint = 'user')

a then in your Resource class:

class UserAPI(Resource):

  def get(self, userId, username=None):
    pass

ANSWER 4

Score 36

@user.route('/<userId>/')  # NEED '/' AFTER LINK
@user.route('/<userId>/<username>')
def show(userId, username=None):
    pass

https://flask.palletsprojects.com/en/1.1.x/quickstart/#unique-urls-redirection-behavior