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Your First Script

This tutorial walks through running your first Python script in LinkCAD’s interactive console.

Open the Console

Go to View → Python Console (Ctrl+Shift+P). A Python prompt appears at the bottom of the window.

Hello World

Type the following and press ↵:

print("Hello from LinkCAD!")

You should see the output in the console.

Exploring the Drawing

The console and script editor define a global named drawing, which always refers to the drawing currently open in LinkCAD. It is None when nothing is loaded.

With a file loaded, you can inspect its structure:

if drawing is None:
    print("Open a file first")
else:
    for cell in drawing.cells:
        print(f"Cell: {cell.name}")


    for layer in drawing.layers:
        print(f"Layer: {layer.name}")

cells and layers are properties, not methods — a noun costs no parentheses. That convention runs through the whole API: shape.area, cell.bounds, polygon.vertices. Only verbs keep their parentheses: shape.destroy(), cell.clone(name).

Counting Shapes

main = drawing.main_cell
print(f"Total shapes in main cell: {len(main.shapes)}")

Or, a little more usefully, per layer:

from collections import Counter


counts = Counter(
    shape.layer.name
    for cell in drawing.cells
    for shape in cell.shapes
    if shape.layer is not None
)


for name, count in counts.most_common():
    print(f"{name}: {count} shapes")

Creating a Drawing from Scratch

A drawing holds the entire database in memory and must be released. Use it as a context manager and that happens automatically:

from linkcad.v1.db import Drawing
from linkcad.v1.geom import Point


with Drawing("first-script") as dwg:
    top = dwg.add_cell("TOP")
    dwg.main_cell = top


    metal = dwg.add_layer("METAL1")


    top.add_polygon(metal, [(0, 0), (10_000, 0), (10_000, 10_000), (0, 10_000)])
    top.add_circle(metal, Point(20_000, 5_000), diameter=6_000)
    top.add_text(metal, "TOP", Point(0, 12_000), height=2_000)


    print(f"{len(top.shapes)} shapes, bounds {top.bounds}")

Geometry is always created by the object that will own it: the drawing makes cells and layers, and the cell makes shapes.

Using the Script Editor

For longer scripts, use the built-in editor:

  1. Open View → Python Script Editor (Ctrl+Shift+E)
  2. Write your script in the editor
  3. Press F5 to run the entire script
  4. Or select lines and press Ctrl+↵ to run just the selection

Next Steps