Python Forum

#! python3
# resizeandaddlogo.py - Resizes all images in the current working directory to fit
# in a 300x300 square, and adds catlogo.png to the lower-right corner

import os
from PIL import Image

SQUARE_FIT_SIZE = 300
LOGO_FILENAME = 'catlogo.png'
logoIm = Image.open(LOGO_FILENAME)
logoWidth, logoHeight = logoIm.size

os.makedirs('withLogo', exist_ok=True)
for filename in os.listdir('.'):
	if not (filename.endswith('.png') or filename.endswith('.jpg')) or filename == LOGO_FILENAME:
		continue  # skip non-image files and the logo file
	im = Image.open(filename)
	width, height = im.size 
	
	if width > SQUARE_FIT_SIZE and height > SQUARE_FIT_SIZE:
		if width > height:
			height = int((SQUARE_FIT_SIZE / width) * height)
			width = SQUARE_FIT_SIZE
		else:
			width = int((SQUARE_FIT_SIZE / height) * width )
			height = SQUARE_FIT_SIZE
		
		print(f'Resizing {filename}.')
		im = im.resize((width, height))
		
print(f'Adding log to {filename}...')
im.paste(logoIm, (width - logoWidth, height - logoHeight), logoIm)

im.save(os.path.join('withLogo', filename))

Error:
Traceback (most recent call last):
  File "C:\Python36\lib\site-packages\PIL\Image.py", line 1974, in save
    format = EXTENSION[ext]
KeyError: ''

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Python36\kodovi\resizeandaddlogo.py", line 34, in <module>
    im.save(os.path.join('withLogo', filename))
  File "C:\Python36\lib\site-packages\PIL\Image.py", line 1976, in save
    raise ValueError('unknown file extension: {}'.format(ext))
ValueError: unknown file extension:

Does anyone understand what exactly is wrong with line 34?

Looks like the lines

print(f'Adding log to {filename}...')
im.paste(logoIm, (width - logoWidth, height - logoHeight), logoIm)
 
im.save(os.path.join('withLogo', filename))

should be indented to be part of the for loop.

after applying your suggestion I get indentation error...

Align the indent correctly to be part of the for loop, in line with the first 'if', 4 spaces.

#! python3
# resizeandaddlogo.py - Resizes all images in the current working directory to fit
# in a 300x300 square, and adds catlogo.png to the lower-right corner

import os
from PIL import Image

SQUARE_FIT_SIZE = 300
LOGO_FILENAME = 'catlogo.png'
logoIm = Image.open(LOGO_FILENAME)
logoWidth, logoHeight = logoIm.size

os.makedirs('withLogo', exist_ok=True)
for filename in os.listdir('.'):
	if not (filename.endswith('.png') or filename.endswith('.jpg')) or filename == LOGO_FILENAME:
		continue  # skip non-image files and the logo file
	im = Image.open(filename)
	width, height = im.size 
	
	if width > SQUARE_FIT_SIZE and height > SQUARE_FIT_SIZE:
		if width > height:
			height = int((SQUARE_FIT_SIZE / width) * height)
			width = SQUARE_FIT_SIZE
		else:
			width = int((SQUARE_FIT_SIZE / height) * width )
			height = SQUARE_FIT_SIZE
		print(f'Resizing {filename}.')
        im = im.resize((width, height))
    print(f'Adding log to {filename}...')
    im.paste(logoIm, (width - logoWidth, height - logoHeight), logoIm)
    im.save(os.path.join('withLogo', filename))

Error:
C:\Python36\kodovi>resizeandaddlogo.py
  File "C:\Python36\kodovi\resizeandaddlogo.py", line 28
    im = im.resize((width, height))
                                  ^
TabError: inconsistent use of tabs and spaces in indentation

Always some problem of this kind...and I never use tab.