Variable-Length Function Parameters

Python supports flexible argument passing using special syntax:

def process_data(*params, **config):
    print(params)
    print(list(config.items()))

process_data(1, 2, name="Zhang", country="China")

Output:

(1, 2)
[('name', 'Zhang'), ('country', 'China')]

The single asterisk (*params) collects positional arguments into a tuple. The double asterisk (**config) collects keyword arguments into a dictionary. Positional arguments must precede keyword arguments in function definitions.

File System Operations

import subprocess

path = '/Users/myuser/mydata/'
result = subprocess.run(
    ['ls', '-t', path + '*.bgeo.sc'], 
    capture_output=True, 
    text=True
)
files = result.stdout.splitlines()
print(files[-2])

Node Hierarchy Traversal

def getAllDescendants(node):
    descendants = []
    for child in node.children():
        descendants.append(child)
        descendants.extend(getAllDescendants(child))
    return descendants

Houdini Network Editor Operations

Node Creation at Cursor Position

network = hou.ui.paneTabOfType(hou.paneTabType.NetworkEditor)
cursor_pos = network.selectPosition()
new_node = network.pwd().createNode("box")
new_node.setPosition(cursor_pos)

Animation Keyframing System

def keyAllParameters():
    parms = hou.pwd().parms()
    current_frame = hou.intFrame()
    
    for p in parms:
        if p.parmTemplate().type() == hou.parmTemplateType.Float:
            p.setKeyframe({
                'frame': current_frame,
                'value': p.eval()
            })

def resetAllParameters():
    parms = hou.pwd().parms()
    for p in parms:
        if p.parmTemplate().type() == hou.parmTemplateType.Float:
            p.deleteAllKeyframes()
            p.set(0.0)

Node Export/Import System

# Export selected nodes
selected = hou.selectedNodes()
with open("/tmp/node_paths.txt", "w") as f:
    for node in selected:
        f.write(node.path() + "\n")

# Import and merge nodes
with open("/tmp/node_paths.txt", "r") as f:
    paths = [line.strip() for line in f if line.strip()]

editor = hou.ui.paneTabOfType(hou.paneTabType.NetworkEditor)
position = editor.selectPosition()
parent = editor.pwd()

merge_node = parent.createNode("merge", "combined_geometry")
for idx, path in enumerate(paths):
    name = path.split("/")[-1]
    obj_merge = parent.createNode("object_merge", f"import_{name}")
    obj_merge.parm("objpath1").set(path)
    obj_merge.parm("xformtype").set(1)
    obj_merge.setPosition((position[0] + idx * 2, position[1]))
    merge_node.setInput(idx, obj_merge)

merge_node.moveToGoodPosition()
merge_node.setDisplayFlag(True)
merge_node.setRenderFlag(True)