Folder commands for Parameter creation in Houdini: https://gfxhacks.com/create-parameters-in-houdini-with-python#creating-folders

houFolderCreation.py

# define new folder
f = hou.FolderParmTemplate("myFolder", "My Folder")

# define new simple folder (no tab)
f = hou.FolderParmTemplate("myFolder", "My Folder", folder_type=hou.folderType.Simple)

# add parameter at bottom of folder
f.addParmTemplate(p)

# remove item from folder (same as for group)
g.remove("id")

# create folder with multiple parameters at once
f = hou.FolderParmTemplate(
	"folder1",
	"Folder 1",
	folder_type=hou.folderType.Simple,
	parm_templates=[
		hou.FloatParmTemplate("parm1", "Parameter 1", 1),
		hou.FloatParmTemplate("parm1", "Parameter 1", 1)
	]
)
g.append(f)

# create multiple folders at once
f = [
    hou.FolderParmTemplate(
		"folder1",
		"Folder 1",
		folder_type=hou.folderType.Simple,
		parm_templates=[
			hou.FloatParmTemplate("parm4", "Parameter 4", 1),
			hou.FloatParmTemplate("parm5", "Parameter 5", 1)
		]
	),
	hou.FolderParmTemplate(
		"folder2",
		"Folder 2",
		folder_type=hou.folderType.Collapsible,
		parm_templates=[
			hou.FloatParmTemplate("parm6", "Parameter 6", 1),
			hou.FloatParmTemplate("parm7", "Parameter 7", 1)
		]
	)
]

for i in f:
	g.append(i)