如何使用python删除特定单词之前的一行

Question

所以我有文本文件file.txt例如

something1
something2
something3
line to be removed
2022-07-21 >>  Ctrl+S
something4
something5
something6
something7
line to be removed
2022-07-21 >>  Ctrl+S

现在如何让它在整个文件中删除Ctrl+S之前的一行。

这样输出文件将是

something1
something2
something3
2022-07-21 >>  Ctrl+S
something4
something5
something6
something7
2022-07-21 >>  Ctrl+S

谢谢

Answer 1

这应该可以按需要工作；

keyword = 'Ctrl+S'
new_content = []

with open('textfile.txt', 'r+') as f:
    content = f.readlines()
    prev_index = 0
    for i, line in enumerate(content):
        if keyword in line:
            new_content += content[prev_index:i - 1]
            prev_index = i
    new_content += content[prev_index:]
with open('textfile.txt', 'w') as f:
    f.write("".join(new_content))

Answer 2

用一个 open 语句试试这个。 希望它可以帮助你。

with open("textfile.txt", "r+") as f:
    lines = f.readlines()
    f.seek(0)
    for pos, line in enumerate(lines):
        if len(lines)-1 !=pos:
            if "Ctrl+S" in lines[pos+1]:
                continue
        f.write(line)
    f.truncate()

Answer 3

你可能会做这样的事情：

with open("python_cisco\programs\list.txt", "r") as f:
    lines = f.readlines() # number of bits not to overload your system
    for i in range(len(lines)):
        try:
            if "Ctrl+S" in lines[i]:
                lines.remove(lines[i - 1])
        except:
            pass

with open("python_cisco\programs\list2.txt", "w") as f:
    for i in lines:
    f.write(i)

这将基本上将列表重写为不同的文件而没有不必要的行