confused about how to use? your guide is too simple

[nTnZone]

first I write this according to your guide:
xml_list_path = os.path.join(sys.path[1],"dataset/label/annotation2021")
convert("xmllist.txt", xml_list_path, "output.json")
and raise a error:FileNotFoundError: [Errno 2] No such file or directory
my xmllist contains all the xml file such as 000001.xml 000002.xml... and each line contains one filename

Second I want to understand your code for fix this error
def convert(xml_list, xml_dir, json_file):
list_fp = open(xml_list, 'r')
json_dict = {"images":[], "type": "instances", "annotations": [],
"categories": []}
categories = PRE_DEFINE_CATEGORIES
bnd_id = START_BOUNDING_BOX_ID
for line in list_fp:
line = line.strip()
print("line:"+line)
print("Processing %s"%(line))
xml_f = os.path.join(xml_dir, line)
print("xml_f:"+xml_f)
tree = ET.parse(xml_f)
root = tree.getroot()
print(type(root))
path = get(root, 'path')
.......
what this 'path' mean? And this script