如何将熊猫DataFrame转换为资源描述框架？

import pandas as pd
from rdflib import Graph, Literal, Namespace, URIRef
from rdflib.namespace import RDF, RDFS

g = Graph()

ns = Namespace("http://example.com/")

class DataFrameResource:
    def __init__(self, df):
        self.df = df

    def to_rdf(self):
        for index, row in self.df.iterrows():
            subject = URIRef(ns["row_" + str(index)])
            g.add((subject, RDF.type, ns["DataFrameRow"]))
            for column, value in row.iteritems():
                predicate = URIRef(ns[column])
                g.add((subject, predicate, Literal(value)))

g.add((ns["DataFrameRow"], RDF.type, RDFS.Class))

df = pd.DataFrame({'Name': ['Alice', 'Bob', 'Charlie'],
                   'Age': [25, 30, 35],
                   'City': ['New York', 'London', 'Paris']})

df_resource = DataFrameResource(df)
df_resource.to_rdf()

print(g.serialize(format="turtle").decode("utf-8"))