v0.20.5 - Fix Uproot TTree creation in from_jsonl_to_root.py (2026-06-05)

What Changed?

This release fixes a FutureWarning in from_jsonl_to_root.py caused by Uproot's upcoming default change from TTree to RNTuple. The assignment syntax root_file["events"] = data is replaced with root_file.mktree("events", data) to explicitly create a TTree. No behavior change for existing users.

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What's New

Main Feature: Explicit TTree creation with mktree()

What it does: Replaces the deprecated assignment syntax with mktree() to suppress the FutureWarning introduced in Uproot v5.7.0+.

How to use it: No changes required. The fix is internal to from_jsonl_to_root.py.

Code example:

# Before (deprecated)
root_file["events"] = branch_dict

# After (explicit TTree)
root_file.mktree("events", branch_dict)

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Installation

Quick Start

# Get the release
git checkout v0.20.5

# Setup
task env:setup

# Run CLI
uv run kazunoko --help

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What's Different from the Last Version?

🐛 Fixed

• examples: use mktree() to explicitly create TTree in from_jsonl_to_root.py (suppresses Uproot FutureWarning for v5.7.0+)

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Is It Safe to Upgrade?

Backward Compatible: Yes

• No API changes. The ROOT output format (TTree) is unchanged.

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Tests Passed

• ✅ Builds without errors
• ✅ commitizen pre-commit hook passed

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Release Details

• Date: 2026-06-05
• Version: v0.20.5
• Files Changed: 1
• Commits: 88afd88

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Next Steps

No planned changes at this time.