VegaFusion Python Embed

1.6.9 verified Fri May 01 auth: no python

VegaFusion Python Embed provides Rust-accelerated Vega expression evaluation and data transformations for use with Vega(-Lite) visualizations. Version 1.6.9 is the latest stable release. The package is maintained by the VegaFusion team and released as needed.

pip install vegafusion-python-embed

Common errors

error ModuleNotFoundError: No module named 'vegafusion.runtime' ↓

cause Installed the wrong package or forgot to install vegafusion-python-embed (vegafusion alone does not include runtime module).

fix

Run: pip install vegafusion-python-embed

error ImportError: cannot import name 'eval_expression' from 'vegafusion' ↓

cause Attempting to import directly from the top-level vegafusion namespace, which does not export those functions.

fix

Use: from vegafusion import runtime; result = runtime.eval_expression(...)

Warnings

gotcha vegafusion-python-embed is a separate package from vegafusion. It bundles the Rust runtime and is intended for embedding in other Python tools. Do not install both vegafusion and vegafusion-python-embed together; they conflict. ↓

fix Choose one: install vegafusion for client-side use (with WASM), or vegafusion-python-embed for server-side / embedding.

deprecated Some runtime functions (e.g., runtime.pre_transform_spec) that were available in earlier versions are now moved to vegafusion-wasm or vegafusion-client packages. Check if you are using deprecated API. ↓

fix Use vegafusion-client or vegafusion-wasm for client-side spec transformations. For the embed package, stick to expression evaluation and data transformation.

Imports

runtime
wrong
```
import vegafusion
```
correct
```
from vegafusion import runtime
```
vegafusion itself is a namespace package; the embed module is accessed via 'vegafusion.runtime'

Quickstart

Import the runtime and evaluate a Vega expression. The embed package bundles the Rust core and is designed for server-side or offline use.

from vegafusion import runtime
import vegafusion as vf
# Example: evaluate a simple Vega expression
result = runtime.eval_expression("2 + 3")
print(result)
# Note: runtime functions are synchronous in the embed package.