import csv
header=['class','name','sex','height','year']
rows=[
[1,'xiaoming','male',168,23],
[1,'xiaohong','female',162,22],
[2,'xiaozhang','female',158,21],
[2,'xiaoli','male',158,21]
]
with open('csvdir.csv','w',newline='')as f: #newline=" "是为了避免写入之后有空行
ff=csv.writer(f)
ff.writerow(header)
ff.writerows(rows)
2.在写入字典序列类型数据的时候，需要传入两个参数，一个是文件对象——f，一个是字段名称——fieldnames，到时候要写入表头的时候，只需要调用writerheader方法，写入一行字典系列数据调用writerrow方法，并传入相应字典参数，写入多行调用writerows
import csv
headers = ['class','name','sex','height','year']
rows = [
{'class':1,'name':'xiaoming','sex':'male','height':168,'year':23},
{'class':1,'name':'xiaohong','sex':'female','height':162,'year':22},
{'class':2,'name':'xiaozhang','sex':'female','height':163,'year':21},
{'class':2,'name':'xiaoli','sex':'male','height':158,'year':21},
]
with open('test2.csv','w',newline='')as f:
f_csv = csv.DictWriter(f,headers)
f_csv.writeheader()
f_csv.writerows(rows)
注意：列表和字典形式的数据写入是不一样的！！！！！！
3.csv的读取，和读取文件差不多：
import csv
with open('test.csv')as f:
f_csv = csv.reader(f)
for row in f_csv:
print(row)
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='')1234567891011
a_name b_name0 1 41 2 52 3 61234
同样pandas也提供简单的读csv方法
import pandas as pddata = pd.read_csv('test.csv')12
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]])12345678910
index a_name b_name0 1 31 2 32 3 41234
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
