python之读写csv文件数据

╰半橙微兮° 2022-01-17 07:21 308阅读 0赞

import csv
    
    with open('./data.csv', 'r') as f:
      reader = csv.reader(f)
      # python 2
     # header = reader.next()
      # python 3x 使用python内置的next
      header = next(reader)
      #获取真正的数据
      for row in reader:
        print(row) # 打印每一行，列表类型，只能按位置索引

以上版本一，是python读csv文件并且遍历数据并且打印数据.

1，python写数据到data.csv

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)

运行结果可以看到如下的结果

![2019061400170030.PNG][]

2,读出csv数据。

import csv
    #没有说明只能读取到第一行
    with open('test2.csv','r')as file:
        reader = csv.reader(file)
        ids = [low[0] for low in reader]
        value = [low[2] for low in reader]
    
    print ('ids',ids)
    print ('value',value)
    
    #读取多行
    id_list = []
    value_list = []
    with open('test2.csv','r')as file:
        reader = csv.reader(file)
        lows = [low for low in reader]
        ids = [low[0] for low in lows]
        value = [low[1] for low in lows]
    
    print ('ids',ids)
    print ('value',value)

运行结果如下

![20190614004340222.PNG][]

3，写入csv数据：

class writer():
        def __init__(self):
            self.dict={
                "标题":"标题",
                "链接":"链接",
                "服务":"服务",
                "dsr":"dsr",
                "店铺名":"店铺名",
                "价格":"店铺名",
                "付款人数":"付款人数",
                "发货地":"发货地"
            }
            out = open("outfile.csv", 'w', newline='')
            self.csv_writer = csv.writer(out, dialect='excel')
            self.csv_writer.writerow(self.dict)
    
        def writer_to(self,key_value):
            self.csv_writer.writerow(key_value)
    
    
    if __name__ == '__main__':
        a=writer()
        new={"链接":"http://www.baidu.com",'标题':'我是标题',}
        a.dict.update(new)
        print(a.dict)
        a.writer_to(a.dict.values())

运行结果：

![20190614002353705.PNG][]

[2019061400170030.PNG]: /images/20220117/bb31aca42cc541379049c7b276d24825.png
[20190614004340222.PNG]: /images/20220117/e8556eec430c4ef7a065ae1ed5708047.png
[20190614002353705.PNG]: /images/20220117/cc938dd84b924d53a34bb95d31ecb345.png