A Python template for creating parameters in Houdini: https://gfxhacks.com/create-parameters-in-houdini-with-python

houParameterTemplate.py

import hou

# get node (find the path in your node's info panel)
n = hou.node("/path/to/node")

# get existing list of parameters for the specified node
g = n.parmTemplateGroup()

# define folders and parameters
f = [
    hou.FolderParmTemplate(
        "folder1",
        "Folder 1",
        folder_type=hou.folderType.Simple,
        parm_templates=[
            hou.FloatParmTemplate("parm1", "Parameter 1", 1),
            hou.FloatParmTemplate("parm2", "Parameter 2", 1)
        ]
    ),
    hou.SeparatorParmTemplate("sep1"),
    hou.ButtonParmTemplate(
        "parm3", 
        "Parameter 3", 
        script_callback='print("Hello World!")',
        script_callback_language=hou.scriptLanguage.Python
    ),
    hou.FolderParmTemplate(
        "folder2",
        "Folder 2",
        folder_type=hou.folderType.Simple,
        parm_templates=[
            hou.FloatParmTemplate("parm4", "Parameter 4", 1),
            hou.FloatParmTemplate("parm5", "Parameter 5", 3)
        ]
    ),
    hou.SeparatorParmTemplate("sep2"),
    hou.ToggleParmTemplate("parm6", "Parameter 6", default_value=True)
]

# for each folder and parameter defined, add to the list
for i in f:
    g.append(i)

# apply changes
n.setParmTemplateGroup(g)