Moving 2 photos from each subfolder to another folder

[DeaD_EyE]

The old functions in os and os.path are very low level and are hard to use.
The Path object gives you more Abstraction.

import shutil
from pathlib import Path


def move_files(sources, destination, extensions=None):
    
    # converting the str to a Path object
    # if it's already a Path object, it
    # will return also a Path object
    destination = Path(destination)
    
    # you've more than one source directory
    # so iterating over this list with possible str or Path objects
    for source in sources:
        # here the same conversion to Path objects happens like before
        source = Path(source)
        
        # checking if it's on the same file system
        # if this is the case, the file can be renamed
        # otherwise the file must be copied
        same_filesystem = source.stat().st_dev == destination.stat().st_dev
        
        for source_path in source.iterdir():
            # continue if source_path is not regular file
            if not source_path.is_file():
                # continue -> back to the top of the inner for-loop
                continue
                
            # checking first if extension is provided
            # and if the suffix is in extensions
            # if the first condition is not True, the
            # second condition is not evaluated
            if extensions and source_path.suffix not in extensions:
                continue
                
            dst_path = destination / source_path.name
            
            # checking if the file on the target already exists
            # and skipping it if it's the case
            if dst_path.exists():
                continue

            # if the file is on the same filesystem
            # then the file could be renamed
            # otherwise the slow copy operation must be used
            if same_filesystem:
                # rename operation on same fs
                source_path.rename(dst_path)
            else:
                # move operation if it's not the same fs
                # move does two operations: copy and then delete the
                # old file
                shutil.move(source_path, dst_path)
                

For example, move_files(["A", "B", "C"], "Q") will rename/move files from directories A, B, C (one level deep) to directory Q. move_files(["A", "B", "C"], "Q", [".jpg", ".png"]) will move only jpg and png files.