<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_size(path):
 """ Returns the size in bytes if `path` is a file, or the size of all files in `path` if it's a directory. Analogous to `du -s`. """

    if os.path.isfile(path):
        return os.path.getsize(path)
    return sum(get_size(os.path.join(path, f)) for f in os.listdir(path))