python怎么写入csv文件

python怎么写入csv文件

import pandas as pd#任意的多组列表a = [1,2,3]
b = [4,5,6]

#字典中的key值即为csv中列名dataframe = pd.DataFrame({a_name:a,b_name:b})#将DataFrame存储为csv,index表示是否显示行名，default=Truedataframe.to_csv("test.csv",index=False,sep=)123456789101a_name b_name0 1 41 2 52 3 6123
同样pandas也提供简单的读csv方法
import pandas as pddata = pd.read_csv(test.csv)1
会得到一个DataFrame类型的data，不熟悉处理方法可以参考pandas十分钟入门
另一种方法用csv包，一行一行写入
import csv

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

#先写入columns_name
writer.writerow(["index","a_name","b_name"])
#写入多行用writerows
writer.writerows([[0,1,3],[1,2,3],[2,3,4]])123456789index a_name b_name0 1 31 2 32 3 4123
读取csv文件用reader
import csvwith open("test.csv","r") as csvfile:
reader = csv.reader(csvfile) #这里不需要readlines
for line in reader:
print line