Chapter02 Sanic Generates Error When Trying to Run src.server:app

[TheGeolama]

sanic is installed in a virutalenv. Within the Chapter02/booktracker folder, I issue this command at the Windows Command prompt:

sanic src.server:app -p 7777 --debug --workers=2

I get this traceback:

Traceback (most recent call last):
File "C:\Program Files\Python310\lib\runpy.py", line 196, in _run_module_as_main
return run_code(code, main_globals, None,
File "C:\Program Files\Python310\lib\runpy.py", line 86, in run_code
exec(code, run_globals)
File "D:\Development\PyCharmProjects\Python-Web-Development-with-Sanic-main\venv\Scripts\sanic.exe_main.py", line 7, in
File "D:\Development\PyCharmProjects\Python-Web-Development-with-Sanic-main\venv\lib\site-packages\sanic_main.py", line 12, in main
cli.run()
File "D:\Development\PyCharmProjects\Python-Web-Development-with-Sanic-main\venv\lib\site-packages\sanic\cli\app.py", line 82, in run
app = self._get_app()
File "D:\Development\PyCharmProjects\Python-Web-Development-with-Sanic-main\venv\lib\site-packages\sanic\cli\app.py", line 135, in get_app
module = import_module(module_name)
File "C:\Program Files\Python310\lib\importlib_init.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "", line 1050, in _gcd_import
File "", line 1027, in _find_and_load
File "", line 1006, in _find_and_load_unlocked
File "", line 688, in _load_unlocked
File "", line 883, in exec_module
File "", line 241, in _call_with_frames_removed
File "D:\Development\PyCharmProjects\Python-Web-Development-with-Sanic-main\Chapter02\booktracker\src\server.py", line 4, in
app = create_app()
File "D:\Development\PyCharmProjects\Python-Web-Development-with-Sanic-main\Chapter02\booktracker\src\utilities\app_factory.py", line 22, in create_app
autodiscover(app, *init_blueprints)
File "D:\Development\PyCharmProjects\Python-Web-Development-with-Sanic-main\Chapter02\booktracker\src\utilities\autodiscovery.py", line 28, in autodiscover
app.blueprint(bp)
File "D:\Development\PyCharmProjects\Python-Web-Development-with-Sanic-main\venv\lib\site-packages\sanic\app.py", line 527, in blueprint
blueprint.register(self, options)
File "D:\Development\PyCharmProjects\Python-Web-Development-with-Sanic-main\venv\lib\site-packages\sanic\blueprints.py", line 357, in register
route = app._apply_route(apply_route)
File "D:\Development\PyCharmProjects\Python-Web-Development-with-Sanic-main\venv\lib\site-packages\sanic\app.py", line 393, in _apply_route
routes = self.router.add(**params)
File "D:\Development\PyCharmProjects\Python-Web-Development-with-Sanic-main\venv\lib\site-packages\sanic\router.py", line 137, in add
route = super().add(**params) # type: ignore
File "D:\Development\PyCharmProjects\Python-Web-Development-with-Sanic-main\venv\lib\site-packages\sanic_routing\router.py", line 243, in add
group.merge(existing_group, overwrite, append)
File "D:\Development\PyCharmProjects\Python-Web-Development-with-Sanic-main\venv\lib\site-packages\sanic_routing\group.py", line 160, in merge
raise RouteExists(
sanic_routing.exceptions.RouteExists: Route already registered: book [GET]

[ahopkins]

Thanks for bringing this up! This looks like it is the result of a change between v21.3 and v21.6 (when the chapter was written). Basically what is happening is the autodiscover is trying to load both the Blueprint and the BlueprintGroup.

I will get a correction for this up probably later today.

[TheGeolama]

Still working on a fix for this?

[ahopkins]

I just pushed a fix. In short, before we add the BlueprintGroup, we make sure to filter out any blueprints attached to it.

[ahopkins]

Please keep me informed of any more challenges you see. ❤️