[Python-Dev] A smarter shutil.copytree ?

[Tarek Ziadé]

Hi,

shutil.copytree is very convenient to make recursive copies, but
os.walk has to be used everytime some filtering
has to be done on the files copied., if you want to avoid copying some files.

The code pattern with os.walk is pretty talkative :

--------------------- copying a source folder to a target folder, but
the pyc/pyo files
os.mkdir(target)
for root, dirs, filenames in os.walk(source):
    root_target = root.replace(source, target)
    for dir_ in dirs:
        target_dir = join(root_target, dir_)
        if os.path.exists(target_dir):
            continue
        os.mkdir(target_dir)
    for filename in filenames:
        filename_source = join(root, filename)
        filename_target = join(root_target, filename)
        if (os.path.exists(filename_target) or
            os.path.splitext(filename) in ('.pyc', '.pyo')):
            continue
        shutil.copyfile(filename_source, filename_target)
--------------------

If we could provide a callable argument to shutil.copytree, this would
allow simplifying a lot the code:

--------------------- copying a source to a target, but the pyc/pyo file
def filtering(source, target):
    return os.path.splitext(filename) not in ('.pyc', '.pyo')

shutil.copytree(source, target, filter_=filtering)
---------------------

This is a very current pattern in my code, and I think this could be
an interesting enhancement to
shutil. So if people think it is a good idea, I can work on a patch
and submit it to the tracker.

Regards

Tarek

-- 
Tarek Ziadé | Association AfPy | www.afpy.org
Blog FR | http://programmation-python.org
Blog EN | http://tarekziade.wordpress.com/