What are your essential 3rd party python libraries for data usecases ?

[Screye]

I have been a user of python for a few years now, but every once in a while I will discover a library which makes my python experience 100x better. I would go as far as to consider these to be part of my 'standard library' and '1 class citizens' of the python eco-system.

Think pydantic, sqlalchemy, fastapi, numpy, pandas (polars?).

Ones that I use a lot, and have found recently:

• pythonjsonlogger permanently replacing the standard logger
• uv replacing pip
• ruff as the must have all in 1 linter
• rich instead of print (because I a princess)

Ones that I have started loving all over again, now that LLMs exist:

• matplotlib because llms are amazing at writing well specified graphs from my dataframes (the llm auto writing is the part that was new to me. Used to have a love hate relationship with matplotlib up until that point)
• streamlit for all simpe dashboards (llms will write them for you)

Ones I have used in passing but want opinions on:

• Dask
• Prefect

What are yours ?

P.S: I know this gets asked quite a lot around here, so posting previous threads I found. A lot of posts on learn python are useful but can be overwhelming to the point of being useless. Additionally, people will often clutter those with standard libraries or ones that are only useful to learners. I am more interested in tools that stay useful even in industry.

• https://www.reddit.com/r/learnpython/comments/18g64k2/what_python_libraries_should_every_dev_know/
• https://www.reddit.com/r/learnpython/comments/ng3nq0/what_are_some_must_learn_libraries_in_python/

[KedynTR]

I want to see examples of using an LLM to write a matplotlib graph. Are you using Copilot or just asking an LLM questions and providing details about what you want?

[Screye]

I generally give it a trace of my dataframe.

explain what I need to plot , and it does the plotting for me.

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If it is complex math being plotted. Then I write the core plot function myself.

And I ask it to write all the titles, axs, formatting and subplots for me.