ezsxf

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

• 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, 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

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

Contributing and license

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