ezdxf - DXF Drawing Manipulation

Warnings

• gotcha Naming your Python script 'ezdxf.py' will cause a circular import error (e.g., 'AttributeError: partially initialized module 'ezdxf' has no attribute 'readfile'').
  Fix: Rename your script to something else, like 'my_dxf_script.py'.
• gotcha Do not directly instantiate DXF entity classes (e.g., `Line(...)`) and try to add them to layouts. Always use the factory methods provided by the layout objects (e.g., `msp.add_line(...)`).
  Fix: Use layout methods like `layout.add_line()`, `layout.add_circle()`, etc., to create and add entities.
• breaking Saving an existing DXF document to an older DXF version can lead to loss of data and attributes that are not supported in the target older version. ezdxf is not a DXF converter.
  Fix: Be aware of the target DXF version when saving. If preserving all data is critical, save to the same or a newer DXF version, or verify compatibility manually.
• gotcha ezdxf does not support creating or editing ACIS (3DSOLID, REGION, SURFACE) data or OLE objects. These are proprietary formats, and ezdxf only reads/preserves them without modification capabilities.
  Fix: Understand that these specific entity types cannot be programmatically generated or altered by ezdxf. They will be preserved if loaded from an existing file, but not editable.
• gotcha For DXF files with structural flaws or minor corruption, directly using `ezdxf.readfile()` may raise exceptions. The `ezdxf.recover` module provides functions (`recover.readfile()`) to load such files by repairing flaws, but it is a slower process.
  Fix: Wrap `ezdxf.readfile()` calls in a `try-except` block for `IOError` and `ezdxf.DXFStructureError`. For untrusted or potentially flawed files, use `doc, auditor = ezdxf.recover.readfile('messy.dxf')`.
• breaking Version 0.10 introduced a complete rewrite of the entity system. While high-level API changes were minimized, users interacting directly with internal tag lists or migrating from very old versions might experience breaking changes. Unknown group codes will be lost if a modified DXF drawing is saved.
  Fix: Review the 'New Entity System' and 'API changes' sections in the v0.10 release notes if migrating from pre-0.10 versions. Rely on the high-level API for robustness.

Install

• pip install ezdxf Install core package
• pip install ezdxf[draw] Install with drawing add-on (for matplotlib/PyQt support)

Imports

• ezdxf

  import ezdxf

  While 'from ezdxf import *' might work, it's generally discouraged in production code due to potential namespace pollution and difficulty in tracing origins. Sticking to 'import ezdxf' and using 'ezdxf.function()' is clearer.

Quickstart

This quickstart demonstrates how to create a new DXF document, add basic geometric entities (a line and a circle) to its modelspace, and save it to a DXF file. This is the fundamental workflow for generating DXF drawings with ezdxf.

import ezdxf

# 1. Create a new DXF R2010 document
doc = ezdxf.new("R2010")

# 2. Add entities to the modelspace (the main drawing area)
msp = doc.modelspace()

# 3. Add a line from (0,0) to (10,0)
msp.add_line((0, 0), (10, 0))

# 4. Add a circle with center (0,0) and radius 5
msp.add_circle((0, 0), 5)

# 5. Save the DXF document
doc.saveas("my_first_drawing.dxf")
print("Created 'my_first_drawing.dxf'")