最常用的一種方法，利用pandas包

import pandas as pd

#任意的多組列表
a = [1,2,3]
b = [4,5,6]    

#字典中的key值即為csv中列名
dataframe = pd.DataFrame({'a_name':a,'b_name':b})

#將DataFrame儲存為csv,index表示是否顯示行名，default=True
dataframe.to_csv("test.csv",index=False,sep=',')

 a_name  b_name
0       1       4
1       2       5
2       3       6
 

同樣pandas也提供簡單的讀csv方法

import pandas as pd
data = pd.read_csv('test.csv')

會得到一個DataFrame型別的data;

另一種方法用csv包，一行一行寫入

import csv

#python2可以用file替代open
with open("test.csv","w") as csvfile: 
    writer = csv.writer(csvfile)

    #先寫入columns_name
    writer.writerow(["index","a_name","b_name"])
    #寫入多行用writerows
    writer.writerows([[0,1,3],[1,2,3],[2,3,4]])
 

index   a_name  b_name
0       1       3
1       2       3
2       3       4

import csv
with open("test.csv","r") as csvfile:
    reader = csv.reader(csvfile)
    #這裡不需要readlines
    for line in reader:
        print line