PyRank
pyeve

cerberus

Lightweight, extensible data validation library for Python
PyPI GitHub Verified repo
No known security advisories. The current version has no OSV.dev malware reports and no critical or high-severity vulnerabilities.

cerberus has 8.2M monthly downloads and 3K GitHub stars. Version 1.3.8 supports Python 3.7+, first published in 2012.

It is minimally maintained under a permissive license, last released in Nov 2025.

It is built on top of importlib-metadata. It is used by 281 tracked packages, including kolo, spool and eve.

GitHub topics include data-validation.

Downloads
Day
190.8K
Week
1.4M
Month
8.2M
Stars
3.3K
Forks
245
Issues
15
Version
1.3.8

Package Insights

What's this?
Score breakdown - each component scores 0-100, weighted by percentage
Maintenance
50
Popularity
73
Adoption
60
Community
50
Provenance
100
How the maintenance status was determined
Last commit
186 days ago
Monthly downloads
8,157,099
Active
Activity within 30 days
Stable
Activity within 31-180 days
• Minimal
Activity within 181-365 days, or no activity data
At Risk
No activity for > 365 days, but > 10,000 monthly downloads
Archived
Repository flagged as archived on GitHub
How the popularity category was determined
Monthly downloads
8,157,099
Stars
3,285
Stars per 1k downloads
0.40
Industry Standard
> 10,000,000 monthly downloads
• Hidden Gem
< 0.5 stars per 1k downloads and > 100,000 monthly downloads
Community Favorite
> 5 stars per 1k downloads
Rising Star
Balanced ratio of stars to downloads
Unknown
Fewer than 1,000 monthly downloads, or no star data
How download momentum is calculated
Week daily avg
198,840
Month daily avg
271,903
Momentum
-26.9%
((week_daily_avg - month_daily_avg) / month_daily_avg) * 100
Python version support tiers
requires_python
>=3.7
Cutting Edge
Minimum supported version is 3.12 or newer
Modern
Minimum supported version is 3.9, 3.10, or 3.11
• Legacy
Supports 3.8 or older (or Python 2)
Unknown
No requires_python specified or unparseable
License categories
License
ISC License
• Permissive
MIT, Apache, BSD, ISC, Unlicense, CC0, etc.
Copyleft
GPL, LGPL, AGPL, MPL, EPL, etc.
Proprietary
Commercial, all rights reserved, custom EULAs
Unknown
No license specified, or none of the above match
How the release cadence was determined
Last release
242 days ago
Total releases
30
Releases/year
2.2
Rapid
Last release within 365 days and > 12 releases/year
• Regular
Last release within 365 days
Slow
Last release 366-730 days ago
Stalled
Last release > 730 days ago, or no releases
Unknown
No usable release date available
How contributor risk was determined
Contributors
52
Monthly downloads
8,157,099
High Load
≤ 2 contributors and ≥ 50,000 monthly downloads
Moderate Load
< 10 contributors and ≥ 500,000 monthly downloads
Low Load
< 25 contributors and ≥ 5,000,000 monthly downloads, or sole maintainer with ≥ 10,000 monthly downloads
• Balanced
Enough contributors for the package's popularity
Unknown
No contributor data available
Engagement
49
 
Issue Burden
4.6
per 1k stars
Discussions
0.0
per 1k stars
Fork Ratio
21.2%
contrib / forks
Stale Release
No
 
PR Velocity
Quiet
 

Weekly Downloads

GitHub Stars

Not all downloads include detailed metadata. Breakdowns reflect the subset that does.

Downloads by OS

Linux 110.3K
macOS 1.4K
Windows 639

Python Versions

3.12
49.5% 50.0K
3.11
25.1% 25.3K
3.10
15.0% 15.2K
3.9
7.2% 7.2K
3.8
3.3% 3.3K

Top Countries

1. US US
81.7K
2. NL NL
12.4K
3. CA CA
4.0K
4. IE IE
3.9K
5. DE DE
2.1K
6. ZA ZA
1.8K
7. IN IN
927
8. AE AE
824
9. GB GB
703
10. CN CN
670
GitHub Topics
Tags from the package's GitHub repository describing what it does.

Package Information

License
ISC License
First Release
October 16, 2012
Last Release
8 months ago
Last Commit
6 months ago
Latest Version
1.3.8
Total Releases
30
Contributors
52
Open PRs
3
Archived
No
Python Versions
3 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14
Wheels
py3
Keywords
validation schema dictionaries documents normalization
Tracking Since
January 6, 2026
Data Updated
July 5, 2026
Data Freshness
Fresh

Links