Skip to content

wolfxl 1.7.0 — public-launch slice (no pivot tables)

Date: 2026-04-27

WolfXL 1.7.0 is the tracked openpyxl-compatible launch slice, not a universal replacement claim. After 23 RFCs across 8 sprints (Δ → Ξ), the construction-side surface tracked for this release is shipped, with one explicit exception: pivot tables are preserved on round-trip but not yet constructible (that's v2.0.0 / Sprint Ν).

TL;DR

  • ✅ Production-ready. PyPI classifier promoted from 4 - Beta to 5 - Production/Stable.
  • ✅ pyproject.toml + Cargo.toml versions sync to 1.7.0. The package version had drifted from the git tag since v0.5; wolfxl.__version__ now reports 1.7.0 correctly.
  • ✅ Worksheet.remove_chart(chart) + Worksheet.replace_chart(old, new). Closes the v1.6.1 release-notes deferral.
  • ✅ chart.title = RichText(...) works. The v1.6.1 known-gap xfail flips to passing.
  • ✅ docs/migration/ rewritten for v1.7. Compatibility Matrix
  • openpyxl-migration walkthroughs cover all 16 chart families, images, encryption, streaming reads, structural ops, modify-mode mutations, rich text.
  • ✅ docs/performance/ refreshed. Read / write / modify-mode / chart-construction speedup tables on a 1k / 10k / 100k row matrix.
  • ✅ Plans/launch-posts.md materialised — HN, Twitter/X, r/Python, dev.to, GitHub Discussions drafts.

What's new

Worksheet.remove_chart(chart)

Mirrors the openpyxl idiom ws._charts.remove(chart):

import wolfxl
from wolfxl.chart import BarChart, Reference

wb = wolfxl.Workbook()
ws = wb.active
ws.append(["Region", "Q1", "Q2"])
ws.append(["NA", 100, 110])

chart = BarChart()
data = Reference(ws, min_col=2, min_row=1, max_col=3, max_row=2)
chart.add_data(data, titles_from_data=True)
ws.add_chart(chart, "E2")

# Decide we don't want it after all:
ws.remove_chart(chart)
wb.save("no_chart.xlsx")

Scope (v1.7): removes a chart that was added via add_chart and has not yet been flushed to disk. Removal of charts that survive from the source workbook (modify mode) is a v1.8 follow-up (needs the patcher to expose a queue_chart_remove alongside the existing queue_chart_add). If you call remove_chart on a chart that wasn't added via add_chart, you get a clear ValueError pointing at the v1.8 follow-up.

Worksheet.replace_chart(old, new)

Convenience for "swap the chart at this anchor":

old_chart = BarChart()
ws.add_chart(old_chart, "G2")

# ... later, with a redesigned chart ...
new_chart = LineChart()
ws.replace_chart(old_chart, new_chart)
# new_chart inherits old_chart's anchor ("G2")
# unless new_chart._anchor was set explicitly first.

The replacement chart inherits the old chart's anchor (so deterministic chart-ID allocation matches the pre-replace layout) unless the caller already set new._anchor explicitly. Wrong type for new raises TypeError; missing old raises ValueError.

chart.title = RichText(...)

In v1.6.1 the only xfail left in tests/test_charts_write.py was test_line_chart_title_rich_text: chart.title= rejected openpyxl-style RichText(bodyPr=..., p=[...]) with a TypeError. Sprint Ξ closes the gap:

from openpyxl.chart.text import RichText
from openpyxl.drawing.text import (
    CharacterProperties,
    Paragraph,
    ParagraphProperties,
    Run as _OpenpyxlRun,    # 3.2.x; or RegularTextRun on 3.1.x
)

bold_run = _OpenpyxlRun(t="Bold", rPr=CharacterProperties(b=True))
red_run  = _OpenpyxlRun(
    t=" Red",
    rPr=CharacterProperties(solidFill=ColorChoice(srgbClr="FF0000")),
)
para = Paragraph(pPr=ParagraphProperties(), r=[bold_run, red_run])

chart = LineChart()
chart.title = RichText(p=[para])     # accepted as of v1.7

TitleDescriptor.__set__ now accepts wolfxl-typed RichText, openpyxl-typed RichText via duck typing, plus the existing str and Title paths. Title.to_dict() additionally coerces openpyxl's ColorChoice-typed solidFill into the hex string the Rust emitter expects.

Version sync

pyproject.toml and Cargo.toml are bumped to 1.7.0. The Rust side is the canonical source — src/lib.rs:41 re-exports env!("CARGO_PKG_VERSION") as wolfxl.__version__, so the bump is a one-line edit in each Cargo.toml package and pyproject. From v1.7 forward, the version stays tracked through both files.

Production / Stable classifier

The PyPI classifier ships as Development Status :: 5 - Production/Stable. This isn't just a vanity move:

  • The read-side surface has been frozen since v1.4 (Sprint Κ — .xls/.xlsb reads) with no deprecations since.
  • The write-side surface has been frozen since v1.6 (Sprint Μ — chart construction) with no deprecations since.
  • The modify-mode surface has been frozen since v1.1 (Sprint Ζ — RFC-035 copy_worksheet).
  • Every parity claim is pinned by tests/parity/openpyxl_surface.py + the strict-xfail ratchet.

The v1.7 release ships with zero strict-xfail markers outside of optional-dependency-not-installed cases.

Documentation refresh

  • docs/migration/openpyxl-migration.md — full rewrite. The pre-v1.7 file was 38 lines covering read-side basics; the v1.7 rewrite covers all 16 chart families, images, encryption (read
  • write), streaming reads, .xlsb/.xls reads, structural ops, modify-mode mutations, and rich text. Includes a "what to validate during migration" + "edge cases worth knowing" + "when to keep openpyxl alongside" section.
  • docs/migration/compatibility-matrix.md — full rewrite. Exhaustive 50+ row table of every openpyxl symbol with v1.7 status, plus ecosystem comparison vs openpyxl 3.1.5 / XlsxWriter / pandas / fastexcel / python-calamine / FastXLSX / rustpy-xlsxwriter.
  • docs/performance/benchmark-results.md — v1.7 numbers on a 1k / 10k / 100k row matrix vs openpyxl 3.1.5 (read / write / modify-mode / chart-construction). Headline:
  • Read 100k rows: 11× speedup
  • Write 100k rows: 10× speedup
  • Touch 1 cell + save (100k-row workbook): 124× speedup
  • copy_worksheet (10k-row + table + DV + CF): 18× speedup
  • docs/performance/methodology.md — extended with construction-side benchmark guidance (chart cache rebuild semantics, image media reuse on copy_worksheet).
  • docs/performance/run-on-your-files.md — extended with a chart-construction microbenchmark + copy_worksheet harness.

Launch-post drafts

Plans/launch-posts.md is materialised with drafts for:

Channel Tone Length
HN ("Show HN") Technical Medium
Twitter / X Direct, hooky 8-tweet thread
Reddit r/Python Detailed, comparative Medium-long
dev.to Long-form narrative Long (outline)
GitHub Discussions Announcement, supportive Medium

Plus a pre-launch + post-launch monitoring checklist.

RFC-046 §13 — legacy chart-dict key sunset

Sprint Μ-prime's integrator finalize taught us that the parse_graphical_properties Rust parser carries a backwards-compatibility shim that accepts BOTH the §10 form (solid_fill + nested ln: {solid_fill, w_emu, prst_dash}) AND the legacy form (fill_color, line_color, line_dash, line_width_emu).

The Python emitter has used the §10 form exclusively since v1.6.1. The legacy form survives only as a Rust-side accept-also for any out-of-tree caller that builds a chart dict by hand and passes it to the (private) wolfxl._rust.serialize_chart_dict helper.

Sunset timeline:

Version Status
v1.7.0 Both forms accepted; documentation-only deprecation.
v2.0.0 Removal — only §10.9 form supported.

No runtime warning is emitted (avoids spurious noise for any caller outside our test suite). v2.0.0 will remove the shim in the same commit that adds the pivot-table chart parser path.

Out of scope (deferred)

  • Pivot table construction — Sprint Ν / v2.0.0. Pivot tables are preserved on modify-mode round-trip; they're just not constructible from scratch in Python yet.
  • Pivot-chart linkage (<c:pivotSource> referencing a pivot cache definition) — Sprint Ν / v2.0.0.
  • Combination charts (multi-plot — bar + line on shared axes) — not on the v1.7 roadmap; v1.7.x if requested.
  • Worksheet.delete_chart_persisted (modify-mode removal of charts that survive from the source workbook) — v1.8 follow-up.
  • OpenDocument (.ods) — out of scope; not on the roadmap.

Acknowledgements

To everyone who file-bugged the v1.6 chart contract gap, the streaming-datetime drift, the RFC-035 cross-RFC composition bugs, and the 100 little things that surface at scale.

Stats (post-1.7.0)

  • python -c "import wolfxl; print(wolfxl.__version__)" → 1.7.0
  • pytest tests/test_charts_write.py tests/test_charts_remove.py tests/test_charts_3d.py → 82 passed, 1 skipped (vs v1.6.1's 75 passed, 1 skipped, 1 xfailed)
  • tests/test_charts_remove.py adds 7 new tests
  • tests/test_charts_write.py::test_line_chart_title_rich_text flips xfail → pass

Pods that landed 1.7.0

  • Pod-α — pyproject.toml / Cargo.toml version bump, Worksheet.remove_chart / replace_chart (tests/test_charts_remove.py), RichText title support (python/wolfxl/chart/title.py), RFC-046 §13 / §14 / §15 documentation.
  • Pod-β — docs/migration/openpyxl-migration.md + docs/migration/compatibility-matrix.md rewrites.
  • Pod-γ — docs/performance/ refresh.
  • Pod-δ — Plans/launch-posts.md drafts.

Sprint Ξ ran without the worktree-fanout pattern (lessons #8-12 from prior sprints made the integrator-inline path safer for small-LOC, mostly-docs slices). All four pods authored on feat/native-writer directly.

RFCs

  • Plans/rfcs/046-chart-construction.md §13 / §14 / §15 — Sprint Ξ additions.
  • Plans/sprint-xi.md — Sprint Ξ tracking doc.

Next

Sprint Ν / v2.0.0 — pivot tables + pivot caches + pivot charts. This is the last construction-side milestone on the openpyxl-parity roadmap. After it ships, any replacement wording still has to pass the public evidence audit; do not promote the old "full openpyxl replacement, period" phrasing as release copy.