from langfuse.callback import CallbackHandler
handler = CallbackHandler(PUBLIC_KEY, SECRET_KEY)

The currently activated Python version 3.10.10 is not supported by the project (^3.11).
Trying to find and use a compatible version. 
Using python3 (3.11.0)
Using version ^1.1.2 for langfuse

Updating dependencies
Resolving dependencies... (0.7s)

Because no versions of pydantic-settings match >2.0.2,<2.0.3 || >2.0.3,<3.0.0
 and pydantic-settings (2.0.2) depends on pydantic (>=2.0.1), pydantic-settings (>=2.0.2,<2.0.3 || >2.0.3,<3.0.0) requires pydantic (>=2.0.1).
And because pydantic-settings (2.0.3) depends on pydantic (>=2.0.1), pydantic-settings (>=2.0.2,<3.0.0) requires pydantic (>=2.0.1).
Because no versions of langfuse match >1.1.2,<2.0.0
 and langfuse (1.1.2) depends on pydantic (>=1.10.7,<2.0), langfuse (>=1.1.2,<2.0.0) requires pydantic (>=1.10.7,<2.0).
Thus, langfuse (>=1.1.2,<2.0.0) is incompatible with pydantic-settings (>=2.0.2,<3.0.0).
So, because my-llm-app depends on both pydantic-settings (^2.0.2) and langfuse (^1.1.2), version solving failed.

ERROR:root:'model_name'
ERROR:root:run not found

def initialize_huggingface_llm(prompt: PromptTemplate, temperature: float, max_length: int) -> LLMChain:
    repo_id = "google/flan-t5-xxl"

    # Experiment with the max_length parameter and temperature
    llm = HuggingFaceHub(
        repo_id=repo_id, model_kwargs={"temperature": temperature, "max_length": max_length}
    )
    return LLMChain(prompt=prompt, llm=llm)

def generate_prompt() -> PromptTemplate:
    # You can play around with the prompt, see the results change if you make small changes to the prompt
    template = """Given the name of the country, give the languages that are spoken in that country. 
    Start with the official languages of the country and continue with the other languages of that country.
    Country: {country}?
    Languages: 
    """

    return PromptTemplate(template=template, input_variables=["country"])

if __name__ == '__main__':
    load_dotenv()

    handler = CallbackHandler(os.getenv('LANGFUSE_PUBLIC_KEY'),
                              os.getenv('LANGFUSE_SECRET_KEY'),
                              os.getenv('LANGFUSE_HOST'))

    # Try other values to see impact on results
    country = "belgium"
    country_max_length = 100
    country_temperature = 0.1

    country_prompt = generate_prompt()

    hugging_chain = initialize_huggingface_llm(prompt=country_prompt,
                                               temperature=country_temperature,
                                               max_length=country_max_length)
    
    print("HuggingFace")
    print(hugging_chain.run(country, callbacks=[handler]))

generation = langfuse.generation(...)
generation.end()

File "/..../lib/python3.10/site-packages/langfuse/callback/langchain.py", line 443, in on_tool_start
    meta.update(
    └ None

sh-3.2$ python3 -m venv env
sh-3.2$ source env/bin/activate
(env) sh-3.2$ python3 -V
Python 3.11.4
(env) sh-3.2$ python3 -m pip install langfuse
Collecting langfuse
  Using cached langfuse-1.0.18-py3-none-any.whl (45 kB)
Collecting ... (skipping a few lines here)
Installing collected packages: pytz, urllib3, typing-extensions, tenacity, sniffio, six, PyYAML, packaging, numpy, mypy-extensions, multidict, idna, h11, frozenlist, charset-normalizer, certifi, attrs, async-timeout, yarl, typing-inspect, SQLAlchemy, requests, python-dateutil, pydantic, numexpr, marshmallow, anyio, aiosignal, langsmith, httpcore, dataclasses-json, aiohttp, langchain, httpx, langfuse
Successfully installed PyYAML-6.0.1 SQLAlchemy-2.0.20 aiohttp-3.8.5 aiosignal-1.3.1 anyio-4.0.0 async-timeout-4.0.3 attrs-23.1.0 certifi-2023.7.22 charset-normalizer-3.2.0 dataclasses-json-0.5.14 frozenlist-1.4.0 h11-0.14.0 httpcore-0.17.3 httpx-0.24.1 idna-3.4 langchain-0.0.286 langfuse-1.0.18 langsmith-0.0.35 marshmallow-3.20.1 multidict-6.0.4 mypy-extensions-1.0.0 numexpr-2.8.6 numpy-1.25.2 packaging-23.1 pydantic-1.10.12 python-dateutil-2.8.2 pytz-2023.3.post1 requests-2.31.0 six-1.16.0 sniffio-1.3.0 tenacity-8.2.3 typing-extensions-4.7.1 typing-inspect-0.9.0 urllib3-2.0.4 yarl-1.9.2
(env) sh-3.2$ python3 -c "from langfuse.model import CreateTrace"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Users/alex/env/lib/python3.11/site-packages/langfuse/__init__.py", line 1, in <module>
    from .client import Langfuse
  File "/Users/alex/env/lib/python3.11/site-packages/langfuse/client.py", line 28, in <module>
    from langfuse.task_manager import TaskManager
  File "/Users/alex/env/lib/python3.11/site-packages/langfuse/task_manager.py", line 8, in <module>
    import backoff
ModuleNotFoundError: No module named 'backoff'
(env) sh-3.2$ python3 -m pip install backoff
Collecting backoff
  Using cached backoff-2.2.1-py3-none-any.whl (15 kB)
Installing collected packages: backoff
Successfully installed backoff-2.2.1
(env) sh-3.2$ python3 -c "from langfuse.model import CreateTrace"
(env) sh-3.2$

pydantic.error_wrappers.ValidationError: 1 validation error for ParsingModel[str]
__root__
  str type expected (type=type_error.str)