Question

我必须从textfile以及上一行和下一行中删除指定的行。我可以删除指定的行，但我不知道如何删除下一行和前一行。这是我的代码

def Parser(line):
global destination
if "CHECKIN" in line:
    splitted = line.split()
    destination = open(ea_xml_dest,'r')
    lines = destination.readlines()
    destination = open(ea_xml_dest,'w')
    sample = str(splitted[5][:-1])
    for i in lines:
        if sample not in i:
            destination.write(i)
    destination.close()
    destination = open(ea_xml_dest,'r')

此脚本不会将包含示例的行移动到新文件中我怎样才能避免上一行和下一行？

Answer 1

您必须找到搜索到的substr行的索引并将其保存到变量（found）。比起原来的lines全部到''之前''的行：以及所有在''之后''之后的行。

found = None
for i,s in enumerate(lines):
  if substr in s:
    found = i
    break

if found: 
  lines = lines[:found-1] + lines[found+2:]

如果未找到任何内容，您只需保留lines变量。

Answer 2

如果这是你可以改变的代码的唯一部分，那么你将不得不做一些非常混乱的事情。

如果你有更多的灵活性，那么你可以这样做：

with open("lines.dat","r") as f:

  previousLine = ""
  lines = []
  checkinCounter = 1

  for line in f:

    if checkinCounter > 0:
      checkinCounter -= 1

    elif "CHECKIN" in line:
      checkinCounter = 2

    else:
      lines.append(previousLine.strip())

    previousLine = line

print lines

其中lines.dat是

1
2
3
4
5
CHECKIN
6
7
8
9
CHECKIN
10
11
12
23
24
156146

输出为['1', '2', '3', '4', '7', '8', '11', '12', '23', '24', '156146']

Answer 3

with open('in.txt') as in_file:
    it = iter(in_file)
    prev = None
    line = it.next()
    while line:
        next = iter.next()
        # condition goes here
        # if line found ....
        prev = line
        line = next

python从文本文件中删除下一行和上一行。基于样本

3 个答案: