Python

Question

我想找到以列表中的单词开头的行。如果找到这个词，我希望它所在的行和上一行被删除。我能够得到行和 previos 一个并打印它们，但我不能不把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

我用这段代码试过了，但我一直收到类型错误：'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

首先记下要复制的行：

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)

如果连续行以 'Text' 或 'Titel'.

开头，deleted_previous_line 的技巧是必要的，以确保它不会删除太多行

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)

Answer 2

您不必立即阅读文件。逐行读取，并存储当前行，但只有在下次读取后才写出，或者不写。

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

Python - 删除行和前面的行（匹配模式模式）

Python - deleting lines and previos lines (matching pattern patterns)

file

pattern-matching

rowdeleting