I’m using a python generator function to provide me with a list of images in the current directory. However I see the function is giving out the entire list twice instead of one time and I have no idea why. I’m using the Python PIL library to create batch thumbnails.
Can anyone point me in the right direction?
Script:
import os
import sys
import Image
class ThumbnailGenerator:
def __init__(self, width, height, image_path, thumb_path):
self.width = width
self.height = height
self.image_path = image_path
self.thumb_path = "%s%s%s" % (self.image_path, os.sep, thumb_path)
def __call__(self):
self.__create_thumbnail_dir()
for filename, image in self.__generate_image_list():
try:
thumbnail = "%s%s%s" % (self.thumb_path, os.sep, filename)
image.thumbnail((self.width, self.height))
image.save(thumbnail, 'JPEG')
print "Thumbnail gemaakt voor: %s" % filename
except IOError:
print "Fout: thumbnail kon niet gemaakt worden voor: %s" % filename
def __generate_image_list(self):
for dirpath, dirnames, filenames in os.walk(self.image_path):
count = 0
for filename in filenames:
try:
image = Image.open(filename)
print '=========', count, filename
count += 1
yield (filename, image)
except IOError:
pass
def __create_thumbnail_dir(self):
try:
os.mkdir(self.thumb_path)
except OSError as exception:
print "Fout: %s" % exception
if __name__ == '__main__':
try:
thumbnail_generator = ThumbnailGenerator(80, 80, '.', 'thumbs')
thumbnail_generator()
except KeyboardInterrupt:
print 'Programma gestopt'
The output of the script at this moment (with some test images) is:
========= 0 124415main_image_feature_380a_ys_full.jpg Thumbnail gemaakt voor: 124415main_image_feature_380a_ys_full.jpg ========= 1 60130main_image_feature_182_jwfull.jpg Thumbnail gemaakt voor: 60130main_image_feature_182_jwfull.jpg ========= 2 assetImage.jpg Thumbnail gemaakt voor: assetImage.jpg ========= 3 devcon-c1-image.gif Fout: thumbnail kon niet gemaakt worden voor: devcon-c1-image.gif ========= 4 image-646313.jpg Thumbnail gemaakt voor: image-646313.jpg ========= 5 Image-Schloss_Nymphenburg_Munich_CC.jpg Thumbnail gemaakt voor: Image-Schloss_Nymphenburg_Munich_CC.jpg ========= 6 image1w.jpg Thumbnail gemaakt voor: image1w.jpg ========= 7 New%20Image.jpg Thumbnail gemaakt voor: New%20Image.jpg ========= 8 samsung-gx20-image.jpg Thumbnail gemaakt voor: samsung-gx20-image.jpg ========= 9 samsung-image.jpg Thumbnail gemaakt voor: samsung-image.jpg ========= 0 124415main_image_feature_380a_ys_full.jpg Thumbnail gemaakt voor: 124415main_image_feature_380a_ys_full.jpg ========= 1 60130main_image_feature_182_jwfull.jpg Thumbnail gemaakt voor: 60130main_image_feature_182_jwfull.jpg ========= 2 assetImage.jpg Thumbnail gemaakt voor: assetImage.jpg ========= 3 devcon-c1-image.gif Fout: thumbnail kon niet gemaakt worden voor: devcon-c1-image.gif ========= 4 image-646313.jpg Thumbnail gemaakt voor: image-646313.jpg ========= 5 Image-Schloss_Nymphenburg_Munich_CC.jpg Thumbnail gemaakt voor: Image-Schloss_Nymphenburg_Munich_CC.jpg ========= 6 image1w.jpg Thumbnail gemaakt voor: image1w.jpg ========= 7 New%20Image.jpg Thumbnail gemaakt voor: New%20Image.jpg ========= 8 samsung-gx20-image.jpg Thumbnail gemaakt voor: samsung-gx20-image.jpg ========= 9 samsung-image.jpg Thumbnail gemaakt voor: samsung-image.jpg
While it should be:
========= 0 124415main_image_feature_380a_ys_full.jpg Thumbnail gemaakt voor: 124415main_image_feature_380a_ys_full.jpg ========= 1 60130main_image_feature_182_jwfull.jpg Thumbnail gemaakt voor: 60130main_image_feature_182_jwfull.jpg ========= 2 assetImage.jpg Thumbnail gemaakt voor: assetImage.jpg ========= 3 devcon-c1-image.gif Fout: thumbnail kon niet gemaakt worden voor: devcon-c1-image.gif ========= 4 image-646313.jpg Thumbnail gemaakt voor: image-646313.jpg ========= 5 Image-Schloss_Nymphenburg_Munich_CC.jpg Thumbnail gemaakt voor: Image-Schloss_Nymphenburg_Munich_CC.jpg ========= 6 image1w.jpg Thumbnail gemaakt voor: image1w.jpg ========= 7 New%20Image.jpg Thumbnail gemaakt voor: New%20Image.jpg ========= 8 samsung-gx20-image.jpg Thumbnail gemaakt voor: samsung-gx20-image.jpg ========= 9 samsung-image.jpg Thumbnail gemaakt voor: samsung-image.jpg
As you can see the generator function is returning the list twice (I verified it and it gets called only once).
@heikogerlach:
os.walk cannot find the thumbnails as I’m walking the filenames of the current directory and the thumbnails get written to a sub-folder of the current directory called ‘thumb’. The list is generated before writing the thumbnails to the ‘thumb’ dir and I verified (using WinPDB) that the thumbnails are not included in the list.
@S.Lott:
Thanks for the advice. os.path.join fixed the problem.
In your debugging, print the full path. I think you’re walking the
thumbssubdirectory after you walk the.directory.Also.
Usually works out better in the long run.
Please do NOT use
__in front of your method names (generate_image_list and create_thumbnail_dir).Do not use
"%s%s%s" % (self.image_path, os.sep, thumb_path)to make path names, useos.path.join.