使用Python从文本文件中删除特定数量的行

AAAAAAAAAAAAAAAAAAAAA              #<--- line 1
BBBBBBBBBBBBBBBBBBBBB              #<--- line 2
CCCCCCCCCCCCCCCCCCCCC              #<--- line 3
DDDDDDDDDDDDDDDDDDDDD              #<--- line 4
EEEEEEEEEEEEEEEEEEEEE              #<--- line 5
FFFFFFFFFFFFFFFFFFFFF              #<--- line 6
GGGGGGGGGGGGGGGGGGGGG              #<--- line 7
HHHHHHHHHHHHHHHHHHHHH              #<--- line 8

忽略“#<---行…”,这只是演示


假设

• 一直如此。。。
• 在前两行之后,我想保留三行。。。

最终结果
最终结果应该是这样的:

CCCCCCCCCCCCCCCCCCCCC              #<--- line 3
DDDDDDDDDDDDDDDDDDDDD              #<--- line 4
EEEEEEEEEEEEEEEEEEEEE              #<--- line 5

删除行:前2行+后3行(即第5行之后)的所有内容

要求的

标准物质
https://thispointer.com/python-how-to-delete-specific-lines-in-a-file-in-a-memory-efficient-way/

def delete_multiple_lines(original_file, line_numbers):
    """In a file, delete the lines at line number in given list"""
    is_skipped = False
    counter = 0
    # Create name of dummy / temporary file
    dummy_file = original_file + '.bak'
    # Open original file in read only mode and dummy file in write mode
    with open(original_file, 'r') as read_obj, open(dummy_file, 'w') as write_obj:
        # Line by line copy data from original file to dummy file
        for line in read_obj:
            # If current line number exist in list then skip copying that line
            if counter not in line_numbers:
                write_obj.write(line)
            else:
                is_skipped = True
            counter += 1

    # If any line is skipped then rename dummy file as original file
    if is_skipped:
        os.remove(original_file)
        os.rename(dummy_file, original_file)
    else:
        os.remove(dummy_file)

delete_multiple_lines('sample.txt', [0,1,2])

此方法的问题可能是,如果文件顶部有1-100行要删除,则必须指定[0,1,2…100]。对吗?


回答
由@sandes提供

以下代码将:

• 删除前63个
• 忽略其余部分

with open("sample.txt", "r") as f:
    lines = f.readlines()
    new_lines = []
    idx_lines_wanted = [x for x in range(63,((63*2)+95))]
    # delete first 63, then get the next 95
    for i, line in enumerate(lines):
        if i > len(idx_lines_wanted) -1:
            break
        if i in idx_lines_wanted:
             new_lines.append(line)

with open("sample2.txt", "w") as f:
    for line in new_lines:
        f.write(line)