我有来自csv文件的数据框：
from flask import request
product_id = request.json['product_id']
url = request.json['url']
website_name = request.json['website_name']
我正在尝试按m_srcaddr进行分组，并将它们的m_fwd_bytes和m_rev_bytes之和除以新列中的1000，名为total_fwd_size和total_rev_size
time m_srcaddr log_type m_type m_fwd_bytes m_rev_bytes
1 1441590784 172.19.139.165 closed 10 295 146
11 1441590785 172.19.139.174 closed 10 441 183
65 1441590792 172.19.139.166 closed 10 441 200
68 1441590792 172.19.139.166 closed 10 3423 461
73 1441590792 172.19.139.172 closed 10 441 379
76 1441590792 172.19.139.172 closed 10 3423 789
77 1441590792 172.19.139.166 closed 10 441 463
81 1441590792 172.19.139.166 closed 10 3423 963
82 1441590793 172.19.139.173 closed 10 295 168
85 1441590793 172.19.139.172 closed 10 4929 542
89 1441590793 172.19.139.166 closed 10 5135 799
93 1441590793 172.19.139.166 closed 10 4929 510
96 1441590794 172.19.139.166 closed 10 0 198
98 1441590794 172.19.139.167 closed 10 0 455
100 1441590794 172.19.139.166 closed 10 4945 495
这不起作用，因为NaN即将推出新创建的列。有没有最好的办法做同样的事情？