How do I copy an entire directory of files into an existing directory using Python?

Question

Run the following code from a directory that contains a directory named bar (containing one or more files) and a directory named baz (also containing one or more files). Make sure there is not a directory named foo.

import shutil
shutil.copytree('bar', 'foo')
shutil.copytree('baz', 'foo')

It will fail with:

$ python copytree_test.py 
Traceback (most recent call last):
  File "copytree_test.py", line 5, in <module>
    shutil.copytree('baz', 'foo')
  File "/System/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/shutil.py", line 110, in copytree
  File "/System/Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/os.py", line 172, in makedirs
OSError: [Errno 17] File exists: 'foo'

I want this to work the same way as if I had typed:

$ mkdir foo
$ cp bar/* foo/
$ cp baz/* foo/

Do I need to use shutil.copy() to copy each file in baz into foo? (After I've already copied the contents of 'bar' into 'foo' with shutil.copytree()?) Or is there an easier/better way?

Answer 1

docs explicitly state that destination directory should not exist:

The destination directory, named by dst, must not already exist; it will be created as well as missing parent directories.

I think your best bet is to os.walk the second and all consequent directories, copy2 directory and files and do additional copystat for directories. After all that's precisely what copytree does as explained in the docs. Or you could copy and copystat each directory/file and os.listdir instead of os.walk.

Answer 2

i would assume fastest and simplest way would be have python call the system commands...

example..

import os
cmd = '<command line call>'
os.system(cmd)

Tar and gzip up the directory.... unzip and untar the directory in the desired place.

yah?