python如何对csv操作

比如csv第n列为qq号，如何在第s列使之加上@qq.com对应每个号

简单点的思路：

csv_name = "test.csv"
n = 3
s = 5

with open(csv_name, "r") as fr:
    lines = fr.readlines()

i = 0
with open(csv_name, "w") as fw:
    for line in lines:
        i += 1
        if i == n:
            qq_line = line.replace(",", "@qq.com,").replace("\n", "@qq.com\n")
        if i == s:
            fw.write(qq_line)
            continue
        fw.write(line)