List the layers of a GIMP xcf file. This also exports the visible layers into a png file.

gimp_xcf_list_layers.py

# This lists the layers of a GIMP xcf file.  This also exports the visible layers into a png file.
#
# Execute the commands:
#
#   curl -O https://bitbucket.org/rgl/make_dmg/downloads/background.xcf
#   gimp -idf --batch-interpreter=python-fu-eval -b - -b 'pdb.gimp_quit(0)' < gimp_xcf_list_layers.py
#
# See http://www.gimp.org/docs/python/
# See http://gimpbook.com/scripting/
#
# -- Rui Lopes (ruilopes.com)
import re
from pipes import quote

path = "background.xcf"
png_path = path.replace(".xcf", ".png")

def flatten_layers(drawable, visible=True):
    for layer in drawable.layers:
        layer_visible = visible and layer.visible
        yield (layer, layer_visible)
        if not hasattr(layer, 'layers'):
            continue
        for l in flatten_layers(layer, layer_visible):
            yield l

image = pdb.gimp_xcf_load(0, path, path)

layers = list(flatten_layers(image))

print 'IMAGE_HEADER width height'
print "IMAGE", image.width, image.height

print 'LAYER_HEADER visible x y width height name'
for layer, visible in layers:
    print "LAYER", visible and "1" or "0", layer.offsets[0], layer.offsets[1], layer.width, layer.height, layer.name

pdb.gimp_image_undo_disable(image)

merged_layer = image.merge_visible_layers(CLIP_TO_IMAGE)

pdb.file_png_save2(
    image,
    merged_layer,
    png_path,
    png_path,
    0,  # interlacing (Adam7)
    9,  # compression level (0-9)
    0,  # save background color
    0,  # save gamma
    0,  # save layer offset
    1,  # save resolution
    0,  # save creation time
    0,  # save comment 
    1   # save color values from transparent pixels
)