Save a Houdini Digital Asset through tool shelf button

saveHDA.py

# Save a Houdini Digital Asset through tool shelf button
def saveHDA(hdaName_to_save):
    'Save a particular HDA.'
    # Get all instances of HDA
    for node in hou.node("/obj").children():
        hdaName = node.type().definition().nodeTypeName()
        if hdaName_to_save in hdaName and (not node.isLocked()):
            node.type().definition().updateFromNode(node)
    
saveHDA("HDA_NAME_TO_SAVE")