Check if installed package are exactly the same to this one.

def check_need_install():
    """Check if installed package are exactly the same to this one.
    """
    md5_root, md5_dst = list(), list()
    need_install_flag = False
    for root, _, basename_list in os.walk(_ROOT):
        if os.path.basename(root) != "__pycache__":
            for basename in basename_list:
                src = os.path.join(root, basename)
                dst = os.path.join(root.replace(_ROOT, _DST), basename)
                if os.path.exists(dst):
                    if md5_of_file(src) != md5_of_file(dst):
                        return True
                else:
                    return True
    return need_install_flag