python读取并写入csv文件

Posted 2020-09-19

新建csvData.csv文件

 1 import csv
 2 
 3 # 读取csv文件方式1
 4 csvFile = open("csvData.csv", "r")
 5 reader = csv.reader(csvFile)  # 返回的是迭代类型
 6 data = []
 7 for item in reader:
 8     print(item)
 9     data.append(item)
10 
11 print(data)
12 csvFile.close()
13 
14 # 读取csv文件方式2
15 with open("csvData.csv", "r") as csvfile:
16     reader2 = csv.reader(csvfile) # 读取csv文件，返回的是迭代类型
17     for item2 in reader2:
18         print(item2)
19 csvFile.close()
20 
21 # 从列表写入csv文件
22 csvFile2 = open(‘csvFile2.csv‘,‘w‘, newline=‘‘) # 设置newline，否则两行之间会空一行
23 writer = csv.writer(csvFile2)
24 m = len(data)
25 for i in range(m):
26     writer.writerow(data[i])
27 csvFile2.close()
28 
29 # 从字典写入csv文件
30 dic = {‘张三‘:123, ‘李四‘:456, ‘王二娃‘:789}
31 csvFile3 = open(‘csvFile3.csv‘,‘w‘, newline=‘‘) 
32 writer2 = csv.writer(csvFile3)
33 for key in dic:
34     writer2.writerow([key, dic[key]])
35 csvFile3.close()

未完待续