csv文件读写处理

1.读取

第一种：

import csv
with open("route.csv","r") as f:
    #reader是一个迭代器
    reader=csv.reader(f)
    next(reader)  #输出结果会去掉行头标题
    for row in reader:
        name=row[0]
        dates=row[-1]
        print({"name":name,"date":dates})

第二种：字典方式读取

import csv
with open("route.csv","r") as f:
    #使用DictReader创建的reader是一个迭代器，遍历迭代器返回的数据是一个字典(有序字典)
    #返回的结果不包含行首的标题
    reader=csv.DictReader(f)
    for row in reader:
        # print(row) #遍历迭代器返回的数据是一个字典(有序字典)
        print(row["昵称"],row["院系信息"])

 2.写入

第一种：

import csv
headers=["username","age","addr"]
values={
    ("张三",23,"满城"),
    ("李四",24,"保定"),
    ("王五",25,"衡水"),
    ("赵六",26,"邯郸")
}
with open("name.csv","w",encoding="utf-8",newline="") as f: #newline换行符为空，默认为\n
    writer=csv.writer(f)
    writer.writerow(headers) #写入行首标题
    writer.writerows(values) #写入多行

第二种：

import csv
headers=["username","age","addr"]
values=[
    {"username":"张三","age":23,"addr":"保定"},
    {"username":"李四","age":23,"addr":"邯郸"},
    {"username":"王五","age":23,"addr":"石家庄"},
    {"username":"赵六","age":23,"addr":"衡水"},
]

with open("name2.csv","w",encoding="utf-8",newline="") as f:
    writer=csv.DictWriter(f,headers)
    #写入表头的时候需要写入writerheader方法
    writer.writeheader()
    writer.writerows(values)