Python convert class list in CSV file via pandas.dataframe

import time
import threading
import datetime
import pandas as pdclass Book():def __init__(self,id,name,author,comment,content,isbn,summary,title,topic):self.id=idself.name=nameself.author=authorself.comment=commentself.content=contentself.isbn=isbnself.summary=summaryself.title=titleself.topic=topicbook_list=[]
t1=datetime.datetime.now()arr=range(1,1000001)
for a in arr:book_list.append(Book(a,f'Name_{a}',f'Author_{a}',f'Comment_{a}',f'Content_{a}',f'ISBN_{a}',f'Summary_{a}',f'Title_{a}',f'Topic_{a}'))print(f'Init time cost {datetime.datetime.now()-t1}')book_data=[]t1=datetime.datetime.now()
for bk in book_list:dic={'Id':bk.id,'Name':bk.name,'Author':bk.author,'Comment':bk.comment,'Content':bk.content,'ISBN':bk.isbn,'Summary':bk.summary,'Title':bk.title,'Topic':bk.topic}book_data.append(dic)
print(f'Convert book_data to list with keyvalue items cost:{datetime.datetime.now()-t1}')excelFile=f'book_data_{datetime.datetime.now().strftime('%Y%m%d%H%M%S%f')}.csv'
t1=datetime.datetime.now()
df=pd.DataFrame(book_data)
df.to_csv(excelFile,encoding='utf-8',index=False)
print(f'Store in csv file cost {datetime.datetime.now()-t1},excel file:{excelFile}')excelFile=f'book_dic_{datetime.datetime.now().strftime('%Y%m%d%H%M%S%f')}.csv'
t1=datetime.datetime.now()
df=pd.DataFrame([bk.__dict__ for bk in book_list])
df.to_csv(excelFile,encoding='utf-8',index=False)
print(f'Store book_dic_ in csv file cost {datetime.datetime.now()-t1},excel file:{excelFile}')