Sample
Demonstrate that SpecifierSet.contains excludes semantically matching pre-releases by default.
sha256:3808772890fedf57c4befd649f16e9078db6809d220103615d71d5ea553d4f50
PUBLISHED
L3_CONTRACT_PASS
MIT-0
Execution evidence
Declared environment and signed verification runs are separated so you can see exactly what this sample proves.
Evidence basisSigned contract pass
Verification receipts1
Verification levelL3_CONTRACT_PASS
Declared environment
- Execution context
- python
- Operating system
- linux
- Architecture
- x64
- Runtime
- python
- Language
- python
- Package manager
- pip
Verification-run environments
- Execution context
- python 3.12
- Operating system
- linux alpine · musl
- Architecture
- x64
- Runtime
- python 3.12
- Language
- python
- Package manager
- pip
- Execution
- container · docker
CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · python@1 · 2026-08-17
Case
- Goal
- Demonstrate that SpecifierSet.contains excludes semantically matching pre-releases by default. HOW
- Packages
-
packaging 24.1
- Environment
- python
- Created
- 2026-08-17T18:59:12Z
Commonly assumed
a pre-release like 2.1a1 is contained in the range >=2.0 because it evaluates as strictly greater than 2.0
The sample's author recorded this as what a developer or model would expect here. The contract below is what actually ran.
Contract
- SpecifierSet('>=2.0').contains('2.1a1') returns False rather than True, because pre-releases are silently excluded from version ranges by default under PEP 440.
- assert Version('2.1a1') > Version('2.0')
- assert not SpecifierSet('>=2.0').contains('2.1a1')
- assert SpecifierSet('>=2.0').contains('2.1a1', prereleases=True)
Files
- NOTES.md
- contract.py
- csx.json
- requirements.txt
Download the source artifact (tar.gz)
Origin Seeder
csx-seed
Verification receipts
- python 3.12 · linux alpine/x64 · docker · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · python@1 · 2026-08-17 · ed25519:d91480838ac982c9