code: def find_packages():
      
      packages = ['pyctools']
      for root, dirs, files in os.walk(os.path.join('src', 'pyctools')):
          package = '.'.join(root.split(os.sep)[1:])
          for name in dirs:
              packages.append(package + '.' + name)
      return packages
docs: Walk source directory tree and convert each sub directory to a
      package name.