uproot3
ROOT I/O in pure Python and Numpy.
Decision gist · record as of 2026-08-14
No, unless you are maintaining legacy code that already depends on uproot3. The package is abandoned (last commit 2021-02-19) and uses outdated dependencies like awkward0. For new physics data pipelines, consider alternatives with active maintenance.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- Requires numpy (1.13.1+), awkward0, uproot3-methods, and cachetools.
- The package is abandoned and may not work with modern Python or ROOT file formats.
- Low friction to install.
License · maintenance · safety
BSD 3-clause (permissive) — BSD 3-clause is permissive, allowing commercial and private use with minimal restrictions. You must include a copy of the license and disclaimer.
last release 2021-02-12 (2009 days) · last repo commit 2021-02-19 · 313 stars · archived
0 known vulnerabilities (OSV.dev, 2026-08-14) · 279,452 downloads/mo, #8,120 on PyPI
Alternatives
Verify before relying
pip install uproot3
import uproot3
file = uproot3.open('data.root')
tree = file['tree_name']
arrays = tree.arrays()- Whether uproot3 works with current ROOT file format versions and modern Python releases
- Whether dependencies like awkward0 remain compatible with current NumPy versions
- Performance characteristics on modern hardware and file sizes
What it is and what it does
uproot3 is a pure-Python I/O library for reading and writing ROOT files, the standard data format in high-energy physics. It uses NumPy to cast blocks of data from ROOT files as NumPy arrays, avoiding the need to install the C++ ROOT framework. The library is designed to stream data into machine learning pipelines and scientific computing workflows.
The package depends on numpy, awkward0, uproot3-methods, and cachetools. It supports reading compressed ROOT files with optional dependencies like lz4 and xxhash, and can export data to Pandas DataFrames. However, the repository is archived and has not been maintained since 2021-02-19, making it a legacy tool for existing workflows rather than a foundation for new projects.
Use it for
- Load particle physics data from ROOT files into NumPy arrays for machine learning model training
- Convert ROOT file histograms and trees to Pandas DataFrames for statistical analysis
- Stream large ROOT datasets lazily into memory-constrained environments using cachetools
- Export ROOT file data to other formats without installing the full C++ ROOT framework
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
No, unless you are maintaining legacy code that already depends on uproot3.
The package is abandoned (last commit 2021-02-19) and uses outdated dependencies like awkward0. For new physics data pipelines, consider alternatives with active maintenance.
Install
uproot3 on PyPI
Before you install
Low friction to install. Maintenance is a concern: the repository is archived and the last commit was 2021-02-19, with the package classified as inactive. If you need active development or bug fixes, this is not the right choice.
Requires numpy (1.13.1+), awkward0, uproot3-methods, and cachetools. The package is abandoned and may not work with modern Python or ROOT file formats.
License in practice
BSD 3-clause is permissive, allowing commercial and private use with minimal restrictions. You must include a copy of the license and disclaimer.
Quickstart
pip install uproot3
import uproot3
file = uproot3.open('data.root')
tree = file['tree_name']
arrays = tree.arrays()Verify before relying
- Whether uproot3 works with current ROOT file format versions and modern Python releases
- Whether dependencies like awkward0 remain compatible with current NumPy versions
- Performance characteristics on modern hardware and file sizes
Package facts
| License | BSD 3-clause permissive |
| Python support | Supports the current Python release >=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.* |
| Install friction | Low. Pure-Python wheel |
| Runtime dependencies | 4 packagesnumpyawkward0uproot3-methodscachetools |
| Maintenance | Abandoned 2,009 days since the last release |
| Last repo commit | repository archived |
| First released | |
| Downloads | 279,452 / month, #8,120 on PyPI 30-day window, as of 2026-08-14 |
| Known vulnerabilities | None known OSV.dev, checked 2026-08-14 |
| Classifiers | Development Status :: 7 - InactiveIntended Audience :: DevelopersIntended Audience :: Information TechnologyIntended Audience :: Science/ResearchLicense :: OSI Approved :: BSD LicenseOperating System :: MacOSOperating System :: POSIXOperating System :: UnixProgramming Language :: PythonProgramming Language :: Python :: 2.7Programming Language :: Python :: 3.5Programming Language :: Python :: 3.6Programming Language :: Python :: 3.7Programming Language :: Python :: 3.8Programming Language :: Python :: 3.9Topic :: Scientific/EngineeringTopic :: Scientific/Engineering :: Information AnalysisTopic :: Scientific/Engineering :: MathematicsTopic :: Scientific/Engineering :: PhysicsTopic :: Software DevelopmentTopic :: Utilities |
Evidence: uproot3-3.14.4-py3-none-any.whl
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See also uproot · uproot3-methods · coffea · xrootd · fastjet · vector · fsspec-xrootd · tinynetrc · mplhep · awkward0