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svgelements — SVG path parsing + transforms

Version: 1.9.6
Type: Pure Python
SPM target: Svgelements
Auto-included by: manim (for SVGMobject)
Total Python modules: 2 (one big file)

SVG parser focused on geometry — path arithmetic, transforms, length / bbox calculations, color/length parsing, full SVG-document traversal. Manim uses it to turn .svg files into mobjects. Implementation is one ~9.7 KLOC file derived from regebro's svg.path and mathandy's svgpathtools, plus a thin re-export __init__.py.

Modules

Module What it does
svgelements.__init__ from .svgelements import * — flat re-export of every public class
svgelements.svgelements The single implementation file. Contains 40+ classes (listed below)

Classes in svgelements.svgelements

Class Purpose
SVG Parse + traverse a full SVG document (SVG.parse("file.svg")) — inherits from Group
SVGElement Abstract base for all SVG elements
SVGLexicalParser Internal recursive-descent parser for path d= strings and transform lists
Group <g> container — list of children + transform
Use <use> — referenced element clone
ClipPath <clipPath>
Pattern <pattern>
Desc, Title <desc>, <title> metadata
Image <image> — bitmap reference (gains rasterization if Pillow is installed)
Text <text>
Shape Base for all geometric shapes (mixes SVGElement, GraphicObject, Transformable)
Path <path> — sequence of PathSegment (M, L, C, Q, A, Z); supports *= with Matrix, .length(), .point(t), .bbox(), += to append segments
Subpath A subsequence of Path between Move commands
Rect, Circle, Ellipse, SimpleLine, Polyline, Polygon Concrete <rect>/<circle>/<ellipse>/<line>/<polyline>/<polygon>
PathSegment Base for path commands
Move, Line, Close (Linear subclass) M, L, Z
QuadraticBezier, CubicBezier (Curve subclass) Q, C
Arc A — exact computation if scipy is importable, polyline approximation otherwise
Matrix 3×3 affine transform — Matrix.scale(s), .rotate(deg), .translate(x,y), .skew(x,y); composition via *; applied to shapes via shape *= matrix
Point 2D point with arithmetic and distance_to / polar_to / angle_to
Angle float subclass — degrees / radians / turns conversion via classmethods
Length Unit-aware (px, pt, pc, mm, cm, in, em, ex, %) — .value(ppi=96, relative_length=…) resolves to user units
Color Hex, rgb(), rgba(), hsl(), named-color parsing; Color.parse(), .hex, .red/.green/.blue/.alpha, Color.distance(a, b)
Viewbox <svg viewBox="..."> parser + viewport→viewbox transform
Transformable, GraphicObject Mixins providing transform, stroke, fill, stroke_width, id, values dict

Plus a SVGELEMENTS_VERSION = "1.9.6" module constant.

iOS notes

  • Pure Python, no native deps — works as-is.
  • File uses CRLF line terminators + ISO-8859-1 source encoding — unusual but tolerated.
  • Arc exact methods (chord length, midpoint at parameter t) prefer scipy.special.ellipe when scipy is available; otherwise falls back to numerical approximation. Either path works on iOS — scipy is shipped.
  • Image rasterization needs Pillow — also shipped, so <image> elements decode fine.
  • Manim's SVGMobject(...) consumes svgelements directly — see manim-deps.md.

Example

from svgelements import SVG, Path, Circle, Rect, Matrix, Color, Length

# 1. Parse a path string
p = Path("M 10 10 L 100 10 L 100 100 Z")
print(p.length())                 # 270.0
print(p.bbox())                   # (10, 10, 100, 100)
print(p.point(0.5))               # midpoint along the path

# 2. Construct + transform shapes
circle = Circle(cx=50, cy=50, r=30, fill=Color("steelblue"))
rect   = Rect(x=10, y=10, width=80, height=60)

m = Matrix.scale(2, 2) * Matrix.translate(100, 0)
circle *= m

# 3. Resolve relative units against a viewport
w = Length("50%").value(relative_length=800)   # 400.0
em = Length("1.5em").value(ppi=96)             # 24.0

# 4. Walk a full document
doc = SVG.parse("/tmp/icon.svg", reify=True)
for el in doc.elements():
    if isinstance(el, Path):
        print(el.id, el.length())