import csv
data = [
    (1,"cat",18),
    (2,"dog",17),
    (3,"tigger",16),
]
f = open('test.csv','a',encoding='utf8',newline='')
writer = csv.writer(f)  # csv.writer()中可以傳一個文件對象
for line in data: # 該data既可以是列表嵌套列表的數據類型也可以是列表嵌套元組的數據類型
    writer.writerow(line)

import csv
data = [
    {'id':1,'name':'dog',"age":18},
    {'id':2,'name':'cat',"age":19},
    {'id':3,'name':'dog',"age":20},
]
f = open('test1.csv','a',encoding='utf8',newline='')  # 指定newline=‘'參數
writer = csv.DictWriter(f,fieldnames=['id','name','age'])
writer.writeheader() # 將字段寫入csv格式文件首行
for line in data:
    writer.writerow(line)