re.error: bad character in group name when using custom formatter in a tag

[asparagusbeef]

This is my code:

@cache(
	ttl=cache_control_ttl(default="7d"), 
	key="user:me:user_id:{token.credentials:auth_jwt()}", 
	tags=["user", "me", "user_id:{token.credentials:auth_jwt()}"]
)
@userRouter.get("/me", tags=['user'], response_model=User_Response)
async def me(client: AsyncClient = Depends(get_http_client), token: HTTPAuthorizationCredentials = Depends(bearer)) -> User_Response:
	response = await client.get(f"{DB_API_URL}/user/me", headers={"Authorization": f"Bearer {token.credentials}"})
	return await handle_web_response(response)

I also tried

@cache(
	ttl=cache_control_ttl(default="7d"), 
	key="user:me:user_id:{token.credentials:auth_jwt()}", 
	tags=["user", "me", "user_id:{auth_jwt(token.credentials)}"]
)

auth_jwt() is defined like so:

@default_formatter.register("auth_jwt")
def _auth_jwt(jwt: str) -> str:
    return authenticate_token(jwt)

Full Traceback:

Traceback (most recent call last):
  File "/usr/local/lib/python3.11/multiprocessing/process.py", line 314, in _bootstrap
    self.run()
  File "/usr/local/lib/python3.11/multiprocessing/process.py", line 108, in run
    self._target(*self._args, **self._kwargs)
  File "/src/venv/lib/python3.11/site-packages/uvicorn/_subprocess.py", line 78, in subprocess_started
    target(sockets=sockets)
  File "/src/venv/lib/python3.11/site-packages/uvicorn/server.py", line 65, in run
    return asyncio.run(self.serve(sockets=sockets))
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/asyncio/runners.py", line 190, in run
    return runner.run(main)
           ^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/asyncio/runners.py", line 118, in run
    return self._loop.run_until_complete(task)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/asyncio/base_events.py", line 654, in run_until_complete
    return future.result()
           ^^^^^^^^^^^^^^^
  File "/src/venv/lib/python3.11/site-packages/uvicorn/server.py", line 69, in serve
    await self._serve(sockets)
  File "/src/venv/lib/python3.11/site-packages/uvicorn/server.py", line 76, in _serve
    config.load()
  File "/src/venv/lib/python3.11/site-packages/uvicorn/config.py", line 433, in load
    self.loaded_app = import_from_string(self.app)
                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/src/venv/lib/python3.11/site-packages/uvicorn/importer.py", line 19, in import_from_string
    module = importlib.import_module(module_str)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<frozen importlib._bootstrap>", line 1204, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1176, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1147, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 690, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 940, in exec_module
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File "/src/app/main.py", line 33, in <module>
    from .api.v1.routers.user_router import userRouter, userAnonRouter
  File "/src/app/api/v1/routers/user_router.py", line 105, in <module>
    @cache(
     ^^^^^^
  File "/src/venv/lib/python3.11/site-packages/cashews/wrapper/decorators.py", line 50, in _decorator
    decorator = decorator_fabric(self, **decor_kwargs)(func)
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/src/venv/lib/python3.11/site-packages/cashews/decorators/cache/simple.py", line 43, in _decor
    backend.register_tag(tag, _key_template)
  File "/src/venv/lib/python3.11/site-packages/cashews/wrapper/tags.py", line 72, in register_tag
    self._tags_registry.register_tag(tag, key_template)
  File "/src/venv/lib/python3.11/site-packages/cashews/wrapper/tags.py", line 19, in register_tag
    self._registry_template[tag].append(template_to_re_pattern(key_template))
                                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/src/venv/lib/python3.11/site-packages/cashews/formatter.py", line 175, in template_to_re_pattern
    return re.compile("^" + pattern + "$", flags=re.MULTILINE)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/re/__init__.py", line 227, in compile
    return _compile(pattern, flags)
           ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/re/__init__.py", line 294, in _compile
    p = _compiler.compile(pattern, flags)
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/re/_compiler.py", line 745, in compile
    p = _parser.parse(p, flags)
        ^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/re/_parser.py", line 989, in parse
    p = _parse_sub(source, state, flags & SRE_FLAG_VERBOSE, 0)
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/re/_parser.py", line 464, in _parse_sub
    itemsappend(_parse(source, state, verbose, nested + 1,
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/re/_parser.py", line 730, in _parse
    source.checkgroupname(name, 1, nested)
  File "/usr/local/lib/python3.11/re/_parser.py", line 307, in checkgroupname
    raise self.error(msg, len(name) + offset)
re.error: bad character in group name 'token\\_credentials' at position 21

Perhaps I am doing something incorrectly but I couldn't find in the docs a reference to using a custom formatter (registered with cashews.default_formatter.register) in a key + tagging it. Assistance will be much appreciated!

[Krukov]

Hello !

Your code looks correct, that is just a bug in library. Unfortunately I ( and probably others ) do not use tags in this way, with advanced templates. That is why it is not stable and have a bugs. So thank you for reporting this issue, it leads to improvements in the library.

The fix is on the way. I will let you know when the fix is released

[Krukov]

Should work with 7.1.0 ( I've just released). Please reopen it the issue still exist

[asparagusbeef]

Thank you so much for the responsiveness and for making this library! It's really appreciated