chore: add mypy

[hassiebp]

Important

Add type annotations to functions across multiple files and integrate mypy for type checking.

• Type Annotations:
  • Add return type annotations to functions in client.py, datasets.py, utils.py, environment.py, error_logging.py, prompt_cache.py, serializer.py, CallbackHandler.py, utils.py, media.py, model.py, and openai.py.
  • Annotate function parameters with specific types, such as Any, Optional, Dict, List, Callable, Union, Literal, and Tuple.
• Mypy Integration:
  • Add mypy as a development dependency in pyproject.toml.
  • Configure mypy settings in pyproject.toml to enforce strict type checking, including disallow_untyped_defs, warn_return_any, and strict_equality.
  • Add mypy overrides for specific modules to ignore missing imports.

^{This description was created by for 150289e. You can customize this summary. It will automatically update as commits are pushed.}

Greptile Summary

Disclaimer: Experimental PR review

Adds comprehensive MyPy static type checking support across the langfuse-python codebase, improving type safety and code maintainability without modifying runtime behavior.

• Added explicit return type annotations and parameter type hints to all core modules (client.py, utils.py, serializer.py)
• Configured strict MyPy settings in pyproject.toml with third-party import overrides
• Fixed potential type-related issues like replacing mutable default arguments in error_logging.py
• Improved type hints in integration modules (langchain, openai) with proper generics and Optional types
• Added comprehensive type annotations in media handling and dataset modules

[greptile-apps]

_{14 file(s) reviewed, 3 comment(s)
Edit PR Review Bot Settings | Greptile}

[greptile-apps]

logic: The return type Any is too permissive and doesn't match the actual Callable[[], None] return type of this function

[greptile-apps]

logic: Missing return value in wrapper function when exception occurs. Should return None explicitly.

[greptile-apps]

logic: The mypy overrides list is comprehensive but missing type ignores for newer dependencies like langgraph. Add langgraph to the overrides list.

Suggested change

	[[tool.mypy.overrides]]
	module = [
	"langchain.*",
	"openai.*",
	"chromadb.*",
	"tiktoken.*",
	"google.*",
	"anthropic.*",
	"cohere.*",
	"dashscope.*",
	"pymongo.*",
	"bson.*",
	"boto3.*",
	"llama_index.*",
	"respx.*",
	"bs4.*",
	"lark.*",
	"huggingface_hub.*",
	"backoff.*",
	"wrapt.*",
	"packaging.*",
	"requests.*",
	"opentelemetry.*"
	]
	ignore_missing_imports = true
	[[tool.mypy.overrides]]
	module = [
	"langchain.*",
	"openai.*",
	"chromadb.*",
	"tiktoken.*",
	"google.*",
	"anthropic.*",
	"cohere.*",
	"dashscope.*",
	"pymongo.*",
	"bson.*",
	"boto3.*",
	"llama_index.*",
	"respx.*",
	"bs4.*",
	"lark.*",
	"huggingface_hub.*",
	"backoff.*",
	"wrapt.*",
	"packaging.*",
	"requests.*",
	"opentelemetry.*",
	"langgraph.*"
	]
	ignore_missing_imports = true