How do I export PSDs as PNGs with py-appscript?

Question

I wrote a script to export PSDs as PNGs with rb-appscript. That's fine and dandy, but I can't seem to pull it off in py-appscript.

Here's the ruby code:

#!/usr/bin/env ruby

require 'rubygems'
require 'optparse'
require 'appscript'

ps = Appscript.app('Adobe Photoshop CS5.app')
finder = Appscript.app("Finder.app")

path = "/Users/nbaker/Desktop/"
ps.activate
ps.open(MacTypes::Alias.path("#{path}guy.psd"))

layerSets = ps.current_document.layer_sets.get

# iterate through all layers and hide them
ps.current_document.layers.get.each do |layer|
    layer.visible.set false 
end 

layerSets.each do |layerSet|
    layerSet.visible.set false
end

# iterate through all layerSets, make them visible, and create a PNG for them
layerSets.each do |layerSet|
    name = layerSet.name.get
    layerSet.visible.set true
    ps.current_document.get.export(:in => "#{path}#{name}.png", :as => :save_for_web, 
                             :with_options => {:web_format => :PNG, :png_eight => false})
    layerSet.visible.set false
end

And here's the apparently nonequivalent python code:

from appscript import *
from mactypes import *

# fire up photoshop
ps = app("Adobe Photoshop CS5.app")
ps.activate()

# open the file for editing
path = "/Users/nbaker/Desktop/"
f = Alias(path + "guy.psd")
ps.open(f)

layerSets = ps.current_document.layer_sets()

# iterate through all layers and hide them
for layer in ps.current_document.layers():
    layer.visible.set(False)  

#... and layerSets  
for layerSet in layerSets:  
    layerSet.visible.set(False)

# iterate through all layerSets, make them visible, and create a PNG for them
for layerSet in layerSets:
    name = layerSet.name()
    layerSet.Visible = True
    ps.current_document.get().export(in_=Alias(path + name + ".png"), as_=k.save_for_web,
                 with_options={"web_format":k.PNG, "png_eight":False})

The only part of the python script that doesn't work is the saving. I've gotten all sorts of errors trying different export options and stuff:

Connection is invalid... General Photoshop error occurred. This functionality may not be available in this version of Photoshop... Can't make some data into the expected type...

I can live with just the ruby script, but all of our other scripts are in python, so it would be nice to be able to pull this off in python. Thanks in advance internet.

Answer 1

Bert,

I think I have a solution for you – albeit several months later. Note that I'm a Python noob, so this is by no means elegant.

When I tried out your script, it kept crashing for me too. However by removing the "Alias" in the export call, it seems to be OK:

from appscript import *
from mactypes import *

# fire up photoshop
ps = app("Adobe Photoshop CS5.1.app")
ps.activate()

# open the file for editing
path = "/Users/ian/Desktop/"
f = Alias(path + "Screen Shot 2011-10-13 at 11.48.51 AM.psd")
ps.open(f)

layerSets = ps.current_document.layer_sets()

# no need to iterate
ps.current_document.layers.visible.set(False)
ps.current_document.layer_sets.visible.set(False)

# iterate through all layerSets, make them visible, and create a PNG for them
for l in layerSets:
    name = l.name()
    # print l.name()
    l.visible.set(True)
    # make its layers visible too
    l.layers.visible.set(True)
    # f = open(path + name + ".png", "w").close()

    ps.current_document.get().export(in_=(path + name + ".png"), as_=k.save_for_web,
                 with_options={"web_format":k.PNG, "png_eight":False})

I noticed, too, that you iterate through all the layers to toggle their visibility. You can actually just issue them all a command at once – my understanding is that it's faster, since it doesn't have to keep issuing Apple Events.

The logic of my script isn't correct (with regards to turning layers on and off), but you get the idea.

Ian