Fangchen Li
Maintainer at NumFOCUS
Bothell, Washington, United States
Summary
🤩
Rockstar🎓
Top SchoolFangchen Li is a software engineer and long-time open-source maintainer with a decade of experience focused on Python tooling, build automation, and data libraries. As a core contributor to pandas and maintainer since 2021, Fangchen has improved complex groupby behaviors, JSON/HDFStore handling, and implemented funded features like directory-aware read_csv, while also contributing to widely used projects such as the benchmarking tool ASV and Numba’s build system. He combines deep engineering chops—CI/CD, dependency and build refactors, and test modernization—with applied research experience from graduate work in physics and EE, bridging scientific computing and production software. Based in Bothell, WA, he brings a practical eye for removing legacy constraints (e.g., dropping old Python versions) and improving developer workflows, often surfacing subtle compatibility and performance fixes that benefit large user communities.
10 years of coding experience
7 years of employment as a software developer
Master of Science - MS, Physics, Master of Science - MS, Physics at Washington University in St. LouisBachelor of Science - BS, Physics, Bachelor of Science - BS, Physics at Gettysburg College
Chinese, English
Github Skills (29)
benchmark10
pytest10
py10
python10
data-science10
setuptools10
testing10
pandas10
benchmarking10
cicd10
gpio10
compiler-compiler10
build-automation10
compiler10
raspberry-pi10
Programming languages (12)
Github contributions (5)
pandas-dev/pandas
Jun 2020 - Nov 2022
Flexible and powerful data analysis / manipulation library for Python, providing labeled data structures similar to R data.frame objects, statistical functions, and much more
Role in this project:
Data Scientist
Data ScientistContributions:119 reviews, 139 commits, 203 PRs in 2 years 5 months
Contributions summary:Fangchen primarily contributed to testing and improving the pandas library's data analysis and manipulation capabilities. Their work focused on enhancing the `groupby` functionality, specifically related to indexing, column aggregation, and the return of columns in the results. Furthermore, they addressed and fixed bugs related to reading JSON data, specifically from file URLs and handling line-format JSON. They also worked on enhancing the HDFStore functionality with options like `min_itemsize`.
pythondatalabeled-datamanipulationdataframes
gpiozero/gpiozero
Oct 2020 - Mar 2021
A simple interface to GPIO devices with Raspberry Pi
Role in this project:Back-end Developer & Automation Engineer
Back-end Developer & Automation EngineerContributions:7 commits, 1 PR in 5 months
Contributions summary:Fangchen contributed to the project by dropping support for older Python versions, specifically Python 3.2, 3.3, and 3.4. This indicates an effort to maintain code compatibility and streamline the supported Python environment. Furthermore, the user modified setup.py, and various other project files. These changes involved refactoring and removing legacy code and dependencies.
raspberry-pipythongpiophysical-computingraspberry
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