“object of type 'NoneType' has no len()” error

Question

I\'m seeing weird behavior on this code:

images = dict(cover=[],second_row=[],additional_rows=[])

for pic in pictures:
    if len(images[\'cover\']) == 0:
              


        

Answer 1

You assign something new to images['cover']:

images['cover'] = pic.path_thumb_l

where pic.path_thumb_l is None at some point in your code.

You probably meant to append instead:

images['cover'].append(pic.path_thumb_l)