delete rows on a csv file depending on pattern python

Question

我是使用 python 处理 csv 文件的新手，我想编写允许我执行以下操作的代码：我有一个模式： pattern="3-5;7;10-16" （可能会有所不同），我想要删除（在那种情况下）第 3 到 5、7 和 10 到 16 行有没有人知道怎么做？

Answer 1

You cannot simply delete lines from a csv. Instead, you have to read it in and then write it back with the accepted values. The following code works:

import csv

pattern="3-5;7;10-16"

off = []
for i in pattern.split(';'):
    if '-' in i:
        off += range(int(i.split('-')[0]),int(i.split('-')[1])+1)
    else:
        off += [int(i)]

with open('test.txt') as f:
    reader = csv.reader(f)
    reader = [','.join(item) for i,item in enumerate(reader) if i+1 not in off]

print reader

with open('input.txt', 'w') as f2:
    for i in reader:
        f2.write(i+'\n')