Python, creating Write node with file parameter

[realdanielh]

Hi,

i would like to create a write node with python and assign the string for the "file" knob at the same time.

nuke.nodes.Write()

just creates an empty write node. How would you go about putting the file destination into the file knob at the same time?

Thanks

[Diogo Girondi]

nuke.createNode('Write', ' file the_Path/to_your/file.here')

or

w = nuke.createNode('Write')
w['file'].setValue('the_Path/to_your/file.here')

Among many other ways.

[realdanielh]

Thanks alot Diogo!

[realdanielh]

I got a problem understanding the way Python handles the statement

w = nuke.createNode('Write')

If you just enter this code, Nuke already creates a write Node. I thought by using this statement, you would simply assign the create command to the variable w. Instead, the command is also executed. How can i stop Nuke from creating the write node, i only want to assign the command to w and then later in the script, i want to execute it by calling w.

[VFXEctropy]

Python "calls it as it sees it".
nuke.createNode('Write') creates a write node and returns the object it just created (a write object at some memory address). By interpreting w = nuke.createNode("Write"), you're not saying "assign w to the command nuke.createNode('Write')", you're saying "Create a node and assign w to that object just created"

But again, python "calls it as it sees it". If you want to only interpret the command under certain conditions (as you appear to do), put it in an if statement.

[Diogo Girondi]

VFXEctropy already explained the bit regarding the variable assignment, as he told you are not assigning w to the command it self, but to what that command returns.

If for any reason you need to evaluate a command later on, you can so something like this:

w = 'nuke.createNode( "Write", inpanel=False )'
eval( w )

This way the w var is assigned to a string 'nuke.createNode("Write", inpanel=False)', so it won't run anything until you evaluate that string by doing eval( w ).

[realdanielh]

Thanks alot guys for explaining that to me. That could come in handy

[alexB]

sorry for hijacking this thread.. what does the "inpanel = False" argument do?

i just noticed i need it if i want a read node to evaluate the informations from a .MOV file.

cheers & thanks

alex

[realdanielh]

It means the properties panel wont be opened when that node is created. Why that should be relevant with your .mov file though i dont know...

[alexB]

ahh good info. thanks.

makes completely no sense, why i need it though, but good to know for my other scripts

cheers

alex