(path)
Create a new file, that must not exist before.
Create a new file, that must not exist before.
Create a new file that must not exist before .
def new_file(path):
    """Create a new file, that must not exist before."""
    if path not in paths:
        file = File(path)
        paths[path] = file
        return file
    else:
        raise ValueError('File already exists: {}'.format(path))
def new_file ( path ) : if path not in paths : file = File ( path ) paths [ path ] = file return file else : raise ValueError ( 'File already exists: {}' . format ( path ) )