Using transforms¶

A transform is a Python class. Each one accepts the parsed tree root and zero or more of its own arguments, manipulates the tree, and (usually) returns the root so the writer can serialize it.

Built-in transforms¶

Transform	What it does
`PrintData`	Writes the tree as readable text to a file or stdout.
`SendTreeToPyXSD`	Re-parses the transformed tree through the full pipeline (useful after structural changes).

Transform syntax¶

Transform calls are class names with parenthesized arguments:

PrintData()
SphereCutter(0.5)

The class name must match the module name containing it, modulo casing and underscores (PrintData resolves to print_data and printData; underscore-insensitive fallback matching is applied).

On the command line, chain calls with > and separate transforms run in order, each seeing the previous transform’s result:

pyxsd -i input.xml -t 'ExpandCell() > PrintData()'

Or place one call per line in a file and pass it with -T:

ExpandCell()
PrintData()

(See examples/legacy/sampleTransformFile.txt.)

Bundled application transforms¶

The crystallography transforms that shipped with pyxsd 0.1 — ExpandCell, SphereCutter, CellSizer, BravaisLattice, CoordViewer, FormatForVisit, plus the Atom/Vector helper libraries — now live in examples/legacy/ and are no longer part of the installed package. To use them:

run pyxsd from that directory (cd examples/legacy), or
copy the transform files you need next to your data, or
pass the module file via your transform library setup.

They expect crystallography-shaped data and are meant as adaptable examples. See examples/legacy/README.md.

Library use¶

When driving pyxsd as a library, transform calls are strings in a list:

parser = PyXSD(
    xmlFileInput="inventory.xml",
    transforms=["PrintData()"],
    transformOutputName="out.xml",
)