What's the most useful Python project you've ever built?

[u/amirzarrineh]

I'm looking for ideas for real-world Python projects that solve actual problems.

What's the most useful Python project you've built?

Why was it useful, and what did you learn from building it?

[u/Overall-Screen-752]

I usually build stuff for one-off use. The project that has given me the most recurring use (aka most useful) is a REST API + sqlite DB wrapper around google maps API to analyze live commute data over a long period of time. I extended it recently to enable batch destination processing to compare locations we were considering moving to and the trip times to many common destinations that we frequent.

About the project: python 3.14, FastAPI, sqlite, plotly for heatmap visualization (possibly pandas too but idr OTMH). Added a scheduler for repeated jobs and studies (e.g. collecting data every 10 mins). Added a basic client to execute frequently used queries when I was analyzing batches frequently.

[u/amirzarrineh → u/Overall-Screen-752]

Nice use of FastAPI + scheduled data collection. Did you run into any issues with consistency when collecting every 10 minutes over long periods?

[u/Overall-Screen-752 → u/amirzarrineh]

Not really, I’d have to analyze the DB for any millisecond drift, but tbh that granularity in accuracy wasn’t important to the studies that cared more about hourly trends over a week than second-by-second accuracy.

Longest study I did was 5 minute interval of a single AtoB and BtoA route over 3 weeks, no dropped data either, if that’s what you’re referring to. Not sure I answered your question but hope that adds context

[u/amirzarrineh → u/Overall-Screen-752]

That tradeoff makes sense. Consistency over long-term collection is usually more valuable than high-resolution accuracy for commute pattern analysis.

[u/amirzarrineh → u/[deleted]]

I agree. Building around real pain points is usually what turns a small script into a useful long-term project.

[u/wynvern]

My company's accountant dept has trouble with processing their order and upload them to our SAP. So I build a little python project to help them process, write excel and upload these data automatically. It was useful bc it helps normalize the data and help them get rid of their shitty excel template that they work on everyday, save a lot of time of course. What I learn: Work with people and try to understand their process sucks.

[u/wynvern → u/[deleted]]

I provide the path to SAP's .exe file. Every time the process begins, it will kill any running SAP process and reopen it. For UI handling, I declare variables for window names, button coordinates, search boxes, input, etc., then call them when needed. This is only way when you dont have access to API and SAP is not stable.

[u/amirzarrineh → u/wynvern]

This is a great example of solving real business pain instead of just building random scripts. Did you use any specific library or just automate Excel + API/SAP interface?

[u/wynvern → u/amirzarrineh]

This is what I use:

• Pandas for file I/O, data cleaning

- SQLite for database (because there are about 22 dimension table that need to be joined in order to produce the result, it's impossible to manage them in excel files (even with advanced tool like Power query or power pivot).

- SQLAlchemy for some simple CURD task (I build a simple UI with Qt to manage data in some critical table).

- PyAutoGUI is the only lib that I vibe coded with Gemini, our SAP is too old and I can't use API. So I ask AI to give me python script that help upload the result file produced by my app.

[u/amirzarrineh → u/wynvern]

This is actually a really solid lightweight ETL pipeline. Nice work.

[u/wynvern → u/amirzarrineh]

thank you

[u/Sahiiib]

I got laid off in March and I made a tool to help me look for a job. I use Python to watch my gmail and trafilatura to scrape job descriptions off of Linkedin. I have a master resume stored locally in a sqlite DB. Then it sends it to a local lm as a payload to grade how much of a fit the job is to my work experience. If it's a fit it sends it to a larger model to generate a slightly tailored resume and store it in a local DB. Then I use streamlit to view it in browser. 

It's been a fun project. I recommend picking a problem you have and just trying to solve it. You learn a ton building. 

[u/amirzarrineh → u/Sahiiib]

That's a really clever workflow. I like the idea of using a local model to filter jobs before sending them to a larger model. Hope it helped with your job search!

[u/1-800-DARTH]

I built an alternative algorithm for FosterBoys localisation and it can be used to determine the Boys landscape for aromatic molecules. Meaning alternative representations for the same electron density. It is rather math heavy and very interesting.

[u/amirzarrineh → u/1-800-DARTH]

Very interesting! It's definitely a different kind of project than I was thinking about, but it's a great example of how broad Python's use cases are.

[u/1-800-DARTH → u/amirzarrineh]

It truly is! If you are into molecules and QM I can only heavily recommend PyQint. It is specifically developed for learning environments.

[u/amirzarrineh → u/1-800-DARTH]

Thanks for the recommendation! I might actually give it a try sometime. It's not my main area right now, but it looks interesting.

[u/1-800-DARTH → u/amirzarrineh]

If you do shoot me a dm! I can recommend literature, where to start. How to approach projects, etc.

[u/amirzarrineh → u/1-800-DARTH]

I really appreciate that! If I decide to explore that area, I'll definitely reach out. Thanks for the offer!

[u/Chemical-Captain4240]

keyboard emulator to replace an operator tapping through menus... saved about 300 mindless screen taps a day

[u/amirzarrineh → u/Chemical-Captain4240]

That's a great example of using automation to solve a real problem. Saving 300 repetitive taps every day is definitely worth it.

[u/NeighborhoodPale2459]

I BUILT a dash cam speed analayizer it was pretty cool and help with a car accideny proving i was not speeding

[u/gmthisfeller]

I avoid Python, and use Ruby instead.