An implementation of chunked, compressed, N-dimensional arrays for Python.
C-Rank Grade: A (Welcoming) - 58/100
External PR Merge Rate: 68%
Response Time: 1d
First Timer Success: 42%
zarr-developers/zarr-python has a recorded first-timer success rate of 41.7%. Repositories ranked A typically provide actionable feedback during code reviews and actively nurture new community contributors.
Maintainers in zarr-developers/zarr-python respond to incoming external pull requests in approximately 31.7 hours on average. Keeping PRs focused on single tasks and ensuring tests pass helps maintainers review faster.
The C-Rank™ system evaluates GitHub projects on a 0–100 scale using real data: PR merge rates, review turnaround time, active maintainer presence, and first-time contributor success. A score of 58.0 places zarr-developers/zarr-python in the A tier.
The external contributor pull request merge rate for zarr-developers/zarr-python is 68.2%, based on public PR activity from non-core contributors.
zarr-developers/zarr-python currently has 1 active issue(s) tagged with beginner-friendly labels like "good first issue", "beginner", or "up-for-grabs".
Balanced & professional review environment in zarr-developers/zarr-python. Maintains strict focus on technical quality and test standards.
Average Response Latency
Tracks hours until a maintainer leaves a review, comment, or PR response.
External Acceptance Rate
Percentage of community pull requests successfully merged into main.
First PR Conversion
Rate at which developers submitting their first repository PR succeed.
Show contributors that your repository actively reviews and merges external pull requests.
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Historical health & responsiveness evolution
External PR acceptance
First PR success rate
50% receive response in
90% receive response in
Maintainer review activity heatmap & prime window prediction
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Detected: UTC
Maintainers are most responsive around 14:00 UTC (14:00 UTC in your timezone). Recommended submission window is Tuesday - Thursday from 12:00 to 16:00 UTC (12:00 - 16:00 UTC local).
Maintainer Strategy: Maintainer Sweet Spot: PRs under 150 lines merge in ~21 hours (85% approval). Large PRs (>500 lines) take ~152 hours (31% approval). Keep your diff compact for rapid review.
Describe the issue linked to the documentation I got really stuck trying to figure out how to use imagecodecs's (relatively) new zarr3-compatible codecs, where I specifically wanted to use the JPEG-XL codec. After cursorily reading the zarr and imagecodecs documentations a few times, I still got stuck and started backtracking through my code until I finally realised that because imagecodecs.zarr.Jpegxl is an ArrayBytesCodec, it should not be passed in as a compressor, but as a serializer. I think this could be covered better in the documentation and doc-strings of zarr3, and perhaps also in the error messages. I am not confident enough in my zarr3 knowledge yet to submit a PR myself, but hopefully you can see where I went wrong in this little example: import numpy as np import zarr import imagecodecs.zarr imagecodecs.zarr.register_codecs() compressor = imagecodecs.zarr.Jpegxl(level=5) ds = np.zeros(shape=(64, 256, 256)) z = zarr.create_array( store=COMPRESSION_TESTS_DIR / "out.zar
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When evaluating whether to contribute to zarr-developers/zarr-python, response velocity and maintainer engagement are crucial. GetMerged continuously tracks pull request trajectories, first-comment latency, and code review rounds to help developers avoid submitting pull requests to backlogged repositories.
Currently, maintainers of zarr-developers/zarr-python acknowledge new external contributions in approximately 1 days+. Out of all submitted pull requests from non-core authors in the last 180-day window, 68.2% were successfully merged into the primary branch.
zarr-developers/zarr-python has a recorded first-timer success rate of 41.7%. Repositories ranked Welcoming typically provide actionable feedback during code reviews and actively nurture new community contributors.
The initial maintainer response time averages ~1 days+. Keeping PRs scoped to single concerns and ensuring CI checks succeed will optimize review turnaround.
The C-Rank™ index scores repositories on a 0 to 100 scale using an objective formula: external PR merge rates, initial response speed, active maintainer count, and first-time contributor retention. A score of 58.0 places zarr-developers/zarr-python in the Welcoming tier.
The external pull request merge rate is 68.2%. GetMerged isolates non-core community contributions so external developers get an accurate benchmark of PR acceptance probability.
Yes, zarr-developers/zarr-python currently has 1 active issue(s) tagged with beginner-friendly labels. You can inspect these directly from the repository issues tab.
All metrics displayed for zarr-developers/zarr-python are automatically retrieved via the public GitHub API and recalculated daily. Insider pull requests submitted by repository owners or organization members are excluded from merge rate calculations to preserve objective external contributor statistics.