---
id: uproot3-methods
version: "0.10.1"
license: BSD 3-clause
license_treatment: permissive
maintenance: abandoned
---

# uproot3-methods — Pythonic mix-ins for ROOT classes.

License: permissive · Maintenance: abandoned · Downloads: 279.6K/mo

## What it is and what it does

uproot3-methods is a companion library to uproot 3.x that adds physics-specific methods to classes automatically generated from ROOT files. It provides convenient operations on particle physics objects like TLorentzVectors and histograms (TH*), allowing you to work with these objects more naturally in Python. The library can also be used standalone to create and manipulate arrays of TLorentzVectors without uproot.

However, this package is deprecated and no longer maintained. It was designed for uproot 3.x and Awkward Array 0.x, both of which are now superseded. The repository was archived in 2021, and the package is explicitly incompatible with modern versions (awkward>=1.0 and uproot>=4.0). For new projects, the scikit-hep team recommends using the vector package instead.

Use it for:

- Working with legacy uproot 3.x codebases that need physics-specific methods on ROOT-derived classes.
- Standalone manipulation of TLorentzVector arrays in older particle physics analysis scripts.
- Accessing histogram methods (TH*) from ROOT files read with uproot 3.x.
- Maintaining existing analysis code that depends on uproot3-methods without upgrading to modern uproot.

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

Adds physics-oriented methods to ROOT file classes, primarily TLorentzVectors and histograms, as a companion library to uproot 3.x for working with particle physics data.

No—do not install for new projects. This package is deprecated, unmaintained since March 2021, and incompatible with modern versions of its dependencies. If you are maintaining legacy code that already uses it, it may continue to work if you pin awkward0 and uproot 3.x, but you should plan to migrate to the vector package and uproot 4.x. For new particle physics work, use vector instead.

## Install

pip install uproot3-methods
uv add uproot3-methods
poetry add uproot3-methods

## Installing uproot3-methods

Before you install: Low install friction with just two runtime dependencies (numpy and awkward0), but the repository is archived and the package is explicitly deprecated—it has not been updated since March 2021 and is incompatible with modern versions of Awkward Array and Uproot.

License in practice: BSD 3-clause is permissive and poses no restrictions on commercial or proprietary use, but the deprecated status means you should expect no ongoing license updates or clarifications.

Quickstart:

pip install uproot3-methods
import uproot3_methods
# Use with uproot3 to access methods on ROOT classes
# or standalone: from uproot3_methods.classes.TLorentzVector import TLorentzVector

Requires awkward0 (Awkward Array 0.x); incompatible with awkward>=1.0 and uproot>=4.0. Package is deprecated and no longer maintained.

Verify before relying:

- Whether existing code depending on this package will continue to work with current Python and NumPy versions despite the lack of maintenance.
- Whether the scikit-hep vector package is a suitable drop-in replacement for new projects needing Lorentz vector functionality.

## Package facts

- License: BSD 3-clause (permissive)
- Python support: unspecified
- Install friction: low
- Maintenance: abandoned
- Downloads: 279.6K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

ROOT TLorentzVector methods, uproot3 physics objects, particle physics array operations, ROOT histogram methods, awkward array physics, HEP data analysis, ROOT file class extensions, deprecated, particle-physics, legacy

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