---
id: igwn-segments
version: "2.1.1"
license: GPL-3.0-or-later
license_treatment: copyleft
maintenance: aging
---

# igwn-segments — Representations of semi-open intervals

License: copyleft · Maintenance: aging · Downloads: 110.5K/mo

## What it is and what it does

igwn-segments provides three core data structures—segment, segmentlist, and segmentlistdict—for working with semi-open intervals. It was forked in 2024 from ligo-segments and is designed to represent time windows or ranges, with built-in operations for combining, querying, and manipulating collections of intervals. The package has no runtime dependencies and is marked Production/Stable, supporting Python 3.9 through 3.14.

The library is primarily used in gravitational-wave physics and astronomy research, where time-interval representation is fundamental. It offers a clean API for interval arithmetic without requiring external dependencies, making it lightweight for projects that need interval logic without heavy computational overhead.

Use it for:

- Represent and query detector uptime windows or data-quality segments in gravitational-wave observatories.
- Manage overlapping time intervals for event selection and filtering in physics data analysis.
- Combine or intersect multiple segmentlists to identify common valid time ranges across datasets.
- Store and retrieve interval metadata using segmentlistdict for labeled segment collections.
- Build interval-based filtering logic in scientific pipelines without external dependencies.

## Worth the install?

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

Provides segment, segmentlist, and segmentlistdict objects for representing and manipulating semi-open intervals in Python.

Yes, if you work with semi-open intervals or time windows in scientific or data-analysis code. The package is stable, dependency-free, and widely used in gravitational-wave research. Install friction is moderate due to compiled wheels, but pre-built binaries exist for common platforms. The copyleft license is a blocker only if you need to distribute proprietary code; for internal or open-source use, it poses no barrier. Maintenance is aging (207 days since last release), so verify active support if you need ongoing updates.

## Install

pip install igwn-segments
uv add igwn-segments
poetry add igwn-segments

## Installing igwn-segments

Before you install: Medium install friction due to compiled wheels across multiple platforms (Python 3.10–3.13, macOS, Linux variants, musl). Last release 207 days ago; maintenance status is aging but package is marked Production/Stable.

License in practice: Licensed under GPL-3.0-or-later (copyleft). Any derivative work or bundled distribution must be released under compatible terms; proprietary or closed-source projects cannot use this without separate licensing.

Quickstart:

pip install igwn-segments

from igwn_segments import segment, segmentlist

s = segment(0, 10)
sl = segmentlist([s])

Requires Python 3.9 or later; compiled wheels available for Python 3.10–3.13 on macOS, Linux (x86_64, aarch64), and musl systems.

Verify before relying:

- Whether the package is actively maintained post-fork or in maintenance-only mode (repo metadata unavailable).
- Performance characteristics and scalability limits for large segmentlists.
- Specific use cases beyond gravitational-wave data analysis where this is commonly applied.

## Package facts

- License: GPL-3.0-or-later (copyleft)
- Python support: supports_current
- Install friction: medium
- Maintenance: aging
- Downloads: 110.5K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

semi-open interval representation, segment manipulation library, time interval handling, segmentlist data structure, interval arithmetic python, gravitational wave segment tools, time window management, interval-arithmetic, time-series, gravitational-waves

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