klayout

library0.30.9pypypi✓ verified 85d ago

KLayout is a layout viewer and editor primarily for integrated circuit layouts (GDSII, OASIS). The `klayout` Python package (v0.30.7) provides a standalone scripting interface to KLayout's powerful database and geometry manipulation functionalities, allowing users to programmatically create, modify, and analyze layouts without requiring the full graphical application. It maintains an active release cadence, with minor updates released frequently to address issues and enhance features, often multiple times a month.

data serialization

pip install klayout

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · KLAYOUT

klayout

datapythonv0.30.9

Install

2.5s avg

Import

114ms

Disk

130MB

Pass rate

8/ 10

Env Coverage8 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v0.30.9 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

glibc

py 3.10

✓ —

✓ 2.8s

py 3.11

✓ —

✓ 2.7s

py 3.12

✓ —

✓ 2.25s

py 3.13

✓ —

✓ 2.45s

py 3.9

✕ build_error

130MB installed

● package 130MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

✓ import klayout.db as db

✗ import pya

For Python scripting, `klayout.db` is the recommended and modern way to access the layout database. `pya` is a legacy module, primarily for backward compatibility within the KLayout application's own interpreter, and may not be reliably available or updated with `pip install klayout`.

Layout

✓ layout = db.Layout()

The `Layout` class is part of the `klayout.db` module.

LayerInfo

✓ layer_info = db.LayerInfo(1, 0)

The `LayerInfo` class for defining layers is part of the `klayout.db` module.

This quickstart demonstrates how to create a new GDSII layout, define a cell and layer, add a simple rectangular shape, and save the result using the `klayout.db` module.

import klayout.db as db # Create a new layout object layout = db.Layout() # Set the database unit (DBU) to 1 nanometer (0.001 micrometers) layout.dbu = 0.001 # Create a top cell named 'TOP' top_cell = layout.create_cell("TOP") # Define a layer (e.g., GDS layer 1, datatype 0) layer_info = db.LayerInfo(1, 0) layer_idx = layout.layer(layer_info) # Add a box to the layer in the top cell # Coordinates are in micrometers if DBU is 0.001 (e.g., 100x200 um) box = db.DBox(0, 0, 100, 200) top_cell.shapes(layer_idx).insert(box) # Save the layout to a GDSII file output_filename = "my_first_layout.gds" layout.write(output_filename) print(f"Layout '{output_filename}' created successfully.")

Debug

Known issues

breakingThe recommended way to access KLayout's database objects transitioned from `pya` to `klayout.db` starting with KLayout v0.30.0. While `pya` might still be available for compatibility, `klayout.db` offers a more consistent and future-proof interface.

fix

Migrate your code to use `import klayout.db as db` and access classes/functions through the `db` alias (e.g., `db.Layout()`, `db.DBox()`).

affects: >=0.30.0

gotchaThe `klayout` Python package (installed via `pip`) provides only the scripting interface. It does NOT include the full KLayout graphical user interface (GUI) application. For the GUI, you must download and install the KLayout application separately from the official website.

fix

Understand that `pip install klayout` is for scripting-only. If you need the GUI, download the appropriate KLayout installer for your operating system from `klayout.de/build.html`.

affects: All versions

gotchaKLayout operates with a 'database unit' (DBU) which determines the internal resolution. All coordinates and dimensions are implicitly in DBU units. If not explicitly set, the default DBU can lead to unexpected scaling.

fix

Always explicitly set `layout.dbu` at the beginning of your script to ensure consistent units (e.g., `layout.dbu = 0.001` for 1nm resolution, meaning coordinates are in micrometers). All input values to geometry functions should then be scaled appropriately to this DBU.

affects: All versions

Errors

Common errors & fixes

ModuleNotFoundError: No module named 'klayout'

The `klayout` Python package has not been installed in your current environment.

fix

Run `pip install klayout` to install the package.

AttributeError: module 'pya' has no attribute 'Layout'

You are trying to use classes from `pya` (e.g., `pya.Layout()`) but are running a `klayout` Python package installation (not the full KLayout application environment) where `pya` might not be exposed directly or the new `klayout.db` interface is expected.

fix

Change your import and object instantiation to use `klayout.db`: `import klayout.db as db; layout = db.Layout()`.

RuntimeError: Layer 1/0 already exists in layout

You are attempting to define or add the same layer information (e.g., `LayerInfo(1, 0)`) multiple times to the same `Layout` object, which is not allowed. `layout.layer()` will return the index of an *existing* layer if it matches the `LayerInfo` provided.

fix

Before creating a new layer index, check if the layer already exists using `layout.find_layer()` or ensure you only call `layout.layer(LayerInfo(...))` once for each unique layer definition. `layout.layer()` is idempotent for existing layer infos.

Upgrade

Version history

0.30.9latest on PyPI · released May 29, 2026

Audit

Dependencies

No dependency data recorded yet.

Agent activity

8 hits · last 30 days

node

Resources

githubhttps://github.com/klayout/klayout ↗

packagehttps://pypi.org/project/klayout/ ↗

homepagehttps://www.klayout.de ↗