Python

Package xpict on PyPI — source under python/xpict/. Paint goes through the Rust extension xpict._native; RDKit is required for the single-mol client layout edge (pip install 'xpict[rdkit]').

pip install 'xpict[rdkit]'

Single molecule

Same shape as JS / Rust: mol → render → to_svg.

from xpict import mol, render, to_svg

benzene = mol("c1ccccc1")
rendered = render(benzene, {
    "color": "#0b6e4f",
    "atom_shade": [0, 0, 0.2, 0, 0, 0.9],
})
svg = to_svg(rendered.scene)

aligned = render(mol("Cc1ccccc1"), {"align_to": benzene})  # or align_to=rendered

align_to accepts a prior Mol or Rendered. Options: color, atom_shade, bond_shade, star_labels, weight, scale, align_to, id.

`color`

Molecule 2 (`align_to`)

`star_labels`

Declarative document

Live nested DepictSpec is Rust-first two-pass (same as JS / Rust):

1. Core plan_edge → EdgePlan
2. Host RDKit process_edge_plan
3. Core render_doc → scenes (chrome applied in Rust)

depict(doc) returns list[Rendered]; render(doc) is a SVG convenience wrapper.

from xpict import depict, render, to_svg

rows = depict({
    "type": "mol",
    "smiles": "CCO",
    "color": "#0b6e4f",
    "shade": {"atoms": [0.0, 0.2, 0.9], "vmin": 0.0, "vmax": 1.0},
})
svg = to_svg(rows[0].scene)

# Or SVG directly:
svg = render({
    "type": "group",
    "children": [
        {"type": "mol", "cxsmiles": "*c1ccccc1Cl |$R1;;;;;$|"},
        {"type": "mol", "smiles": "c1ccccc1O"},
    ],
})

Ethanol

CX `|$R1;;;;;$|`

Phenol

Contracts: DepictSpec / MolNode in xpict.contracts.depict. Chem scripts: Label markup.

• Python autodoc
• Install