Error 404 on leaflet.py example

[Galeras14]

Hi
I created a web-app based on the leaflet.py example. It has worked fine for several years but after a few month since I did not use (Jan 2023), I get a "urllib.error.HTTPError: HTTP Error 404: Not Found".

So, I got back to the leaflet.py code from flexx readthedocs and test it as is --> the example return the same error.

What has change since the beginning of the year that makes this example to stop working ?

Thanks for any help,

[almarklein]

I can reproduce that it does not work. The first exception is when the script tries to obtain https://cdnjs.cloudflare.com/ajax/libs/leaflet//1.0.3/images/marker-icon.png. However, it works fine when I copy-paste that link in the browser. Same for https://cdnjs.cloudflare.com/ajax/libs/leaflet//1.0.3/leaflet.js when I comment the lines that downloads the icons.

So it may be related to the user agent - perhaps leaflet is trying to prevent non-browsers from using the API

[jrversteegh]

It looks like it needs an "Accept-Encoding" header.

wget https://cdnjs.cloudflare.com/ajax/libs/leaflet//1.0.3/images/marker-icon.png

doesn't work, but

wget --header='Accept-Encoding: gzip, deflate, br' https://cdnjs.cloudflare.com/ajax/libs/leaflet//1.0.3/images/marker-icon.png

does.

[almarklein]

Thanks @jrversteegh, that explains it, and I manage to get the example working again in #742.

@Galeras14 Could you please check whether #742 fixes it for you to?

[Galeras14]

Hi, thanks a lot for your help. However I'm still having trouble.
I get this error message from _get data function:

assert res.ok, f"{res.status_code}: {res.reason}"
AssertionError: 404: Not Found

In addition, I'm now having a warning message:

/Users/admin/PycharmProjects/Genealogie/env/lib/python3.7/site-packages/urllib3/init.py:38: NotOpenSSLWarning: urllib3 v2.0 only supports OpenSSL 1.1.1+, currently the 'ssl' module is compiled with 'LibreSSL 2.8.3'. See: urllib3/urllib3#3020
exceptions.NotOpenSSLWarning,

Not sure if it is Mac environment or if it is because I'm using Python 3.8.

[almarklein]

Is that the system Python 3.8? Have you tried upgrading to the latest urllib3 using e.g. pip install -U urllib3?

[Galeras14]

Yes, I'm in the latest version of urllib3, 2.0.7

[Galeras14]

I've kind of solve the issue of urllib3 following #3020 issue on urllib3.
Still, the leaflet.py example give me this error, even we the suggested modifications:

Traceback (most recent call last):
File "/Users/admin/PycharmProjects/Genealogie/sample/ui/essai.py", line 82, in
flx.assets.add_shared_data(icon, _get_data('images/%s' % icon))
File "/Users/admin/PycharmProjects/Genealogie/sample/ui/essai.py", line 53, in _get_data
assert res.ok, f"{res.status_code}: {res.reason}"
AssertionError: 404: Not Found

[almarklein]

Mmm. It's pretty annoying that leaflet produces a 404, and not a more meaningful error code. This way there is no way to see whether the problem is the header or your wifi being down 😕

I tried #742 and I got the same error. It looks like I was trying out some stuff and pushed the wrong version. I updated that PR to the version that works for me too. Sorry for that!

edited: I initially linked to the wrong pr above because of a typo, which I now fixed

[Galeras14]

With your modification, the example works for me and my app works again.
Thanks a lot !