ezsxf

A fast SXF parser, SFC writer and drawing converter for Python, powered by Rust and PyO3. Python 3.9 or later is supported.

日本語: SXF 形式の図面（SFC・P21）を Python で読み、編集し、書き出すライブラリです。説明はこのページの下にあります。

• Parse P21/SFC from a file path, text or bytes, with strict or lenient recovery.
• Create, edit and save SFC geometry, text, styles, groups, dimensions and hatches.
• Add elements, fills and shared parts in a single validated batch; export P21/P2Z with dimensions, hatches, attributes and images.
• Deliver drawings with SAF attributes and TIFF/JPEG dependencies.
• Export DXF or plot drawings with the optional matplotlib backend.

Installation

python -m pip install ezsxf

For plotting:

python -m pip install "ezsxf[plot]"

The core package has no runtime Python dependencies. Prebuilt wheels are available for Linux x86-64/ARM64, Windows x86-64 and macOS x86-64/ARM64. Building from source requires Rust; see Contributing.

Quick start

import ezsxf

doc = ezsxf.new_sfc("drawing.sfc", name="Drawing", paper="A1", orientation="landscape")
layer = doc.add_layer("Structure")
color = doc.add_color((32, 96, 160))
doc.add_line((10, 10), (100, 50), layer=layer, color=color)
doc.add_circle((50, 50), 10, layer=layer)
doc.add_text("SXF 日本語", (10, 80), height=3.5)  # estimates a monospaced box width
doc.save("drawing.sfc")
doc.save_p21("drawing.p21")

parsed = ezsxf.parse_sfc("drawing.sfc", strict=True)
ezsxf.write_sfc(parsed, "copy.sfc")
print(len(parsed["typed_features"]))

Use parse_p21 for P21 input. For existing SFC edits, start with edit_sfc(parsed). SFC output uses CP932 and validates the complete model before saving. Excess precision or unencodable text raises an error. Drawings with external SAF/image files should be delivered with the bundle APIs.

CLI

python -m ezsxf parse sfc drawing.sfc --pretty
python -m ezsxf to-dxf drawing.sfc drawing.dxf
python -m ezsxf resave-sfc drawing.sfc copy.sfc
python -m ezsxf to-p21 drawing.sfc drawing.p21

Run python -m ezsxf --help or see the CLI guide.

Supported scope

Format	Support
SFC	All 34 SXF Ver.3.1 feature types are parsed with resolved hierarchy, style codes and attribute attachments. Saving and supported editing APIs retain the SFC model.
P21/P2Z output	AP202 output from SFC models includes curves/cubic splines, point markers, text, dimensions/leaders, fills/hatches, styles, subfigures and attributes. P21 bundles and P2Z include validated SAF/images. See P21 writing and bulk authoring/preflight.

Model preservation and third-party CAD display/re-export have separate limits. See compatibility for Japanese text, backslashes, groups, SAF and images. The package does not claim OCF certification.

Documentation

Start with the documentation index, or choose a guide:

• Reading P21/SFC and parse results
• Saving existing SFC drawings
• Basic SFC creation, editing and style codes
• P21 export and interoperability checks
• Complex elements, groups, dimensions and hatches
• SAF attributes, images and bundle delivery
• Title-block attribute names
• DXF conversion and plotting

日本語

ezsxf は、SXF 形式の図面（SFC・P21）を Python で読み、編集し、書き出すライブラリです。SXF は、国土交通省の電子納品で使われる CAD データ交換の形式です。中身は Rust で、CAD ソフトは要りません。

• 読む: SFC と P21（ファイル、文字列、バイト列から。厳密に読むか、読めない箇所を飛ばして読むかを選べる）
• 作る・直す: SFC の図形、文字、線種と色、グループ、寸法、ハッチ
• 書き出す: SFC、P21・P2Z（寸法、ハッチ、属性、画像を含む）、DXF
• 表示する: matplotlib での描画（ezsxf[plot]）

python -m pip install ezsxf

import ezsxf

parsed = ezsxf.parse_sfc("drawing.sfc", strict=True)  # P21 は parse_p21
print(len(parsed["typed_features"]))
ezsxf.write_sfc(parsed, "copy.sfc")

コマンドラインでは python -m ezsxf to-dxf drawing.sfc drawing.dxf で DXF に、python -m ezsxf to-p21 drawing.sfc drawing.p21 で P21 にできます。

OCF 検定を受けたソフトではありません。ほかの CAD での表示と再保存については compatibility を見てください。

関連するライブラリ: Jw_cad の JWW は ezjww、DWG は ezdwg、複数の形式を 1 つの中間表現で扱うなら cad2d-ir。インストールせずにブラウザで SFC・P21 を開く・変換するなら zumen-gate が使えます。

Contributing and license

See Contributing for source setup and checks, and Code of Conduct for participation guidelines. MIT licensed; see LICENSE.