/svg.path

SVG path objects and parser

Primary LanguagePython

svg.path

svg.path is a collection of objects that implement the different path commands in SVG, and a parser for SVG path definitions.

Usage

There are four path segment objects, Line, Arc, CubicBezier and QuadraticBezier.`There is also a Path object that acts as a collection of the path segment objects.

All of these objects have a .point() and a .length() function.

All coordinate values for these functions are given as complex values, where the .real part represents the X coordinate, and the .imag part representes the Y coordinate.

The .point() function will return the X and Y coordinates of a point on the path, where the point is given as a floating point value where 0.0 is the start of the path and 1.0 is end end.

The .length() function will return the path segment or paths length. This is in some cases done by geometric approximation and for this reason may be very slow.

There is also a parse_path() function that will take an SVG path definition and return a Path object.

Classes

These are the SVG path segment classes. See the SVG specifications for more information on what each parameter means.

  • Line(start, end)
  • Arc(start, radius, rotation, arc, sweep, end)
  • QuadraticBezier(start, control1, control2, end)
  • CubicBezier(start, control1, control2, end)

In addition to that, there is the Path class, which is instantiated with a sequence of path segments:

  • Path(*segments)

That Path class is a mutable sequence, so it behaves like a list.

Examples

This SVG path example draws a triangle:

>>> from svg.path import parse_path, Path, Line, QuadraticBezier
>>> path1 = parse_path('M 100 100 L 300 100 L 200 300 z')

You can format SVG paths in many different ways, all valid paths should be accepted:

>>> path2 = parse_path('M100,100L300,100L200,300z')

And these paths should be equal:

>>> path1 == path2
True

You can also build a path from objects:

>>> path3 = Path(Line(100+100j,300+100j), Line(300+100j, 200+300j), Line(200+300j, 100+100j))

And it should again be equal to the first path:

>>> path1 == path2
True

Paths are mutable sequences, you can slice and append:

>>> path1.append(QuadraticBezier(300+100j, 200+200j, 200+300j))
>>> len(path1[2:]) == 2
True

Todo

This module should have a way to generate path definitions from a path, for completeness.

Licence

This module is under a CC0 1.0 Universal licence. http://creativecommons.org/publicdomain/zero/1.0/