use of shutil.copytree with ENOTDIR exception

[Gribouillis]

I would like to make a script to copy an entire tree for testing (folder, sub-folders, files).
I need all but the files are too big in the source and I don't need what's in them.

This is somewhat contradictory, but you could perhaps try the following

from pathlib import Path

def my_copy(src, dst):
    # create an empty file instead of actually copying a file
    Path(dst).touch()

# Source
src = '/mysourcepath'
  
# Destination
dest = '/mydestinationpath'
  
shutil.copytree(src, dest, dirs_exist_ok=True, copy_function=my_copy)