python读取csv文件

csv格式数据

import csv

csv数据保存，包括三种方式：

1. 直接写入csv文件;
   写入：一条或者多条数据

import csv
header = ['line1','line2','line3']
rows = [[1,2,3],[4,5,6],[7,8,9]]
with open('test.csv','w') as f:
    file = csv.writer(f)
    file.writerow(header)
    file.writerows(rows)

2. 写入字典：
   写入：包括写入头部，写入字典类型内容

import csv
header = ['line1','line2','line3']
rows = {{'line1':1,'line2':2,'line3':3},
        {'line1':4,'line2':5,'line3':6},
        {'line1':7,'line2':8,'line3':9}}
with open('dict.csv','w', newline='') as f:
    file = csv.DictWriter(f,header)
    file.writeheader()
    file.writerows(rows)

3. 读取数据，读取所有列数据，读取某一列数据并打印

# 打印所有结果:
import csv
def readFileRows():
    with open('test.csv','r') as f:
        file = csv.reader(f)
        for line in file:
            print(line)
readFile()

# 如下类型结果：
['ip地址', '端口', '地址']
['115.53.18.58', '9999', '河南濮阳']
['218.91.112.161', '9999', '江苏扬州']
['117.91.132.152', '9999', '江苏扬州']
['114.230.69.167', '9999', '江苏扬州']
['112.85.166.122', '9999', '江苏南通']
['116.208.55.163', '9999', '湖北襄阳市宜城']
['222.189.190.187', '9999', '江苏扬州']
['116.208.11.181', '9999', '湖北襄阳']
['180.119.141.239', '9999', '江苏扬州']

# 打印第一个字段：
def readFileItem():
    with open('test.csv','r') as f:
        file = csv.reader(f)
        for line in file:
            print(line[0])
readFile()
# 如下结果：
# ip地址
115.53.18.58
218.91.112.161
117.91.132.152
114.230.69.167
112.85.166.122
116.208.55.163
222.189.190.1