csv文件处理

一、读取csv文件：

import csv

with open('stock.csv','r') as fp:
	reader = csv.reader(fp)
	titles = next(reader)
	for x in reader:
		print(x)

这样操作，以后获取数据的时候，就要通过下表来获取数据。如果想要在获取数据的时候通过标题来获取。那么可以使用DictReader。示例代码如下：

import csv

with open('stock.csv','r') as fp:
  reader = csv.DictReader(fp)
  for x in reader:
    print(x['turnoverVol'])

二、写入数据到csv文件：

写入数据到csv文件，需要创建一个writer对象，主要用到两个方法。一个是writerow，这个是写入一行。一个是writerows，这个是写入多行。示例代码如下：

import csv

headers = ['name','age','classroom']
values = [
  ('zhiliao',18,'111'),
  ('wena',20,'222'),
  ('bbc',21,'111')
]
with open('test.csv','w',newline='') as fp:
  writer = csv.writer(fp)
  writer.writerow(headers)
  writer.writerows(values)

也可以使用字典的方式把数据写入进去。这时候就需要使用DictWriter了。示例代码如下：

import csv

headers = ['name','age','classroom']
values = [
  {"name":'wenn',"age":20,"classroom":'222'},
  {"name":'abc',"age":30,"classroom":'333'}
]
with open('test.csv','w',newline='') as fp:
  writer = csv.DictWriter(fp,headers)
  writer = csv.writeheader()
  writer.writerow({'name':'zhiliao',"age":18,"classroom":'111'})
  writer.writerows(values)