Changing parameters from a python script

[Yalf]

Hello, I am new to Houdini. I am creating a building generation tool.
I want to randomize parameters of my "controller", which is just a null node with parameters, that control the buildings length, height, number of windows etc.
I want to randomize these parameters with a python script last of all nodes in the network. 

This is how I try to do it, but it doesn't work and I don't understand the error.

nrOfWindows = `chs("../controller/nrOfVertWin")`
print nrOfWindows
nrOfWindows = nrOfWindows + 1
print nrOfWindows
`chs("../controller/nrOfVertWin")` = nrOfWindows

Any help is appreciated, thanks!

[vtrvtr]

`chs...` is a hscript syntax. It's better to use full python if you're going to use python.

Something like
 

import random

controller_node = hou.pwd().parent().node("controller")

windows_parm = controller_node.parm("nOfVertWin")

windows_parm.set(random.randint(0, 5))

This would randomize between 0 and 5.

 

[Yalf]

Thank you, this works great!

If I could just bother you with one more question that would be even better!

How do I re-initialize a python node? If I want this random number to change every time I click the python node?
If I change something in the script it will re-initialize, but that is a bit tedious. Is there a better way?

[vtrvtr]

You can try forcing the cook of a node with `node.cook(force=True)`. But usually you would make a button that would let the user randomize whatever on demand.

You can also take a look at PDG to make a graph that constructs your assets.

[Yalf]

Oh right, that sounds great!
Thanks so much for all the help!