Question

我有以下代码：

import csv
input_file = csv.reader(open('template.csv','r+')) #template.csv has 10 lines
output = open('output.csv', 'wb')
wr = csv.writer(output, quoting=csv.QUOTE_ALL)

elem = [1,2,3,4,5]

for i in elem:
    wr.writerows(input_file)

由于'template.csv'文件有10行，我希望输出10 x 5行 - 但只有10行。

如何嵌套writerow / rows循环？

Answer 1

你input_file是一个迭代器，一旦筋疲力尽就不会为你回到起点。将结果存储在列表中并写下：

input_file = csv.reader(open('template.csv','r+')) #template.csv has 10 lines
input_lines = list(input_file)

Answer 2

writerows ：将根据您在csv.writer中设置的规则创建csv，例如

wr = csv.writer(csvfile, delimiter='\n') #this will output each element in input_file 
                                         #as a separate line

#Loop it 5 times you should have your 5 x 10 lines printed to the file
for i in elem[0:4]:
    wr.writerows(input_file)

writerow（）或writerows（）循环

2 个答案: