ValueError: urls must start with a leading slash

I know somewhere I made a mistake but downloading and running it plainly gave me this error. I can understand somewhere in the routing the error is but I can find it, Can you help?

Traceback (most recent call last): File "app.py", line 17, in <module> app.register_blueprint(charts) File "C:\Users\c_thv\AppData\Local\Continuum\Anaconda2\envs\coffeemug\lib\site-packages\flask\app.py", line 64, in wrapper_func return f(self, *args, **kwargs) File "C:\Users\c_thv\AppData\Local\Continuum\Anaconda2\envs\coffeemug\lib\site-packages\flask\app.py", line 951, in register_blueprint blueprint.register(self, options, first_registration) File "C:\Users\c_thv\AppData\Local\Continuum\Anaconda2\envs\coffeemug\lib\site-packages\flask\blueprints.py", line 151, in register endpoint='static') File "C:\Users\c_thv\AppData\Local\Continuum\Anaconda2\envs\coffeemug\lib\site-packages\flask\blueprints.py", line 76, in add_url_rule view_func, defaults=defaults, **options) File "C:\Users\c_thv\AppData\Local\Continuum\Anaconda2\envs\coffeemug\lib\site-packages\flask\app.py", line 64, in wrapper_func return f(self, *args, **kwargs) File "C:\Users\c_thv\AppData\Local\Continuum\Anaconda2\envs\coffeemug\lib\site-packages\flask\app.py", line 1043, in add_url_rule rule = self.url_rule_class(rule, methods=methods, **options) File "C:\Users\c_thv\AppData\Local\Continuum\Anaconda2\envs\coffeemug\lib\site-packages\werkzeug\routing.py", line 603, in __init__ raise ValueError('urls must start with a leading slash') ValueError: urls must start with a leading slash

[christabor]

It looks like there is an invalid url somewhere in your flask app. Are you using the existing example app, or importing it into your own app instance? If the latter, make sure all your url routes have a leading slash, e.g.:

@app.route('foo/bar/')
def foobar():
    pass

would need to become:

@app.route('/foo/bar/')
def foobar():
    pass

[ShaileshSarda]

Hello, I have tried all the possible approaches but still having the same issue. ValueError: urls must start with a leading slash

I am not getting where exactly I need to fix this issue.