How to delete a line before specific word with python

Question

so I have text file file.txt e.g

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

now how do I make it delete one line before the word Ctrl+S in the whole file.

So that the outputfile will be

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

Thank you

Answer 1

This should work as desired;

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))