<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def is_valid(file_path):
 """ Check to see if a file exists or is empty. """

    from os import path, stat

    can_open = False

    try:
        with open(file_path) as fp:
            can_open = True
    except IOError:
        return False

    is_file = path.isfile(file_path)

    return path.exists(file_path) and is_file and stat(file_path).st_size > 0