Question

我想找到以列表中的单词开头的行。如果找到了该词，我希望它所在的行和前一行被删除。我能够得到该行和previos并打印它们，但是我无法避免不将它们传递给我的输出文件。 F.e。：

输入：

This is not supposed to be deleted.
This shall be deleted. 
Titel

This is not supposed to be deleted.
This is not supposed to be deleted

输出：

This is not supposed to be deleted.

This is not supposed to be deleted.
This is not supposed to be deleted

我使用此代码进行了尝试，但是我不断收到TypeError：'str'对象不支持项目分配

with open(file1) as f_in, open(file2, 'w') as f_out:
    lines = f_in.read().splitlines()
    for i, line in enumerate(lines):
        clean = True
        if line.startswith(('Text', 'Titel')):
            for (line[i-1]) in lines:
                clean = False
            for line in lines:
                clean =False
        if clean == True:
            f_out.write(line)

Answer 1

您不必一次读取文件。相互读取各行，并存储当前行，但仅在下次读取后才将其写出。

with open("file1") as finp, open("file2","w") as fout:

         lprev=""
         for line in finp:

             if line.startswith("Titel") or line.startswith("Text"):
                 lprev=""
                 continue
             if lprev:
                 fout.write(lprev)
             lprev=line

         if lprev:
             fout.write(lprev)  # write out the last line if needed

Answer 2

首先跟踪要复制的行：

lines_to_keep = []
with open(file1) as f_in:
    deleted_previous_line = True
    for line in f_in:
         if line.startswith(('Text', 'Titel')):
              if not deleted_previous_line:
                    del lines_to_keep[-1]
              deleted_previous_line = True
              continue
         deleted_previous_line = False
         lines_to_keep.append(line)

如果连续的行以“文本”或“标题”开头，则使用deleted_previous_line的技巧是必要的，以确保它不会删除过多的行。

然后将其写入您的输出文件

with open(file2, 'w') as f_out:
    f_out.writelines(lines_to_keep)

Python-删除行和previos行（匹配模式模式）

2 个答案: