hou.parm("../button/input").evalAsFloatAtFrame(hou.frame()+3)

import random


# data input parm
input_parm_path = '../button/input'


# data output parm
sibling_nodes_prefix = 'box'
out_parm = '/ry'


# settings for randomization
# random frame offset (how much to depart from original frame)
rand_offset_from = hou.parm('../button/a_int').eval()
rand_offset_to = hou.parm('../button/b_int').eval()
# used to get the same results twice
seed = hou.parm('../button/c_int').eval()
random.seed(seed)
# fix for b_int
if rand_offset_to <= rand_offset_from:
    rand_offset_to = rand_offset_from+1
    hou.parm('../button/b_int').set(rand_offset_to)


# select all box* and put in list
items_list = []
parent_node_path = '/obj/geo1/' # todo: make procedural
parent_node_children = hou.node(parent_node_path).children()
for child in parent_node_children:
    if sibling_nodes_prefix in child.name():
        items_list.append(child.path())


# fix for imported py code (node, not hip)
hou.parm('/obj/geo1/chopnet1/export1/path').set('')
hou.parm('/obj/geo1/chopnet1/export1/path').set('input')


def a():
    for each in items_list:
        r = random.randrange(int(rand_offset_from),
                             int(rand_offset_to))
        child_parm_path = each+out_parm
        child_parm = hou.parm(child_parm_path)
        hou_keyframe = hou.Keyframe()
        hou_keyframe.setTime(0)
        hou_keyframe.setExpression('hou.parm(\
"'+input_parm_path+'").\
evalAsFloatAtFrame(hou.frame()+'+str(r)+')', \
        hou.exprLanguage.Python)
        child_parm.setKeyframe(hou_keyframe)