How to generate __init__.py in all subdirectories of current directory in cmake?

Question

I use an out-of-tree builds with CMake. I have a CMake custom command that generates *_pb2.py files from proto-files. Since proto-files may reside in an unknown number of subdirectories (package namespace), like $SRC/package1/package2/file.proto, then the build directory will contain something like $BLD/package1/package2/file_pb2.py.

I want to implicitly make packages from auto-generated *_pb2.py files and, thus, I want to automagically generate __init__.py files in all subfolders ($BLD/package1, $BLD/package1/package2, etc.) and then install them.

How can I do that?

P.S. I've tried macro from CMake : How to get the name of all subdirectories of a directory? (changed GLOB to GLOB_RECURSE) but it returns only subdirs that contain files. I can't get package1 subdir from example above.

Answer 1

If you are working under a *NIX os (including mac) you could use the shell find command like:

ROOT="./"
for DIR in $(find $ROOT -type d); do
    touch $DIR/__init__.py
done

or with a python script:

from os.path import isdir, walk, join

root = "/path/to/project"
finit = '__init__.py'
def visitor(arg, dirname, fnames):
    fnames = [fname for fname in fnames if isdir(fname)]
    # here you could do some additional checks ...
    print "adding %s to : %s" %(finit, dirname)
    with open(join(dirname, finit), 'w') as file_: file_.write('')

walk(root, visitor, None)