if else condition issue

[gontajones]

You have to use readlines() to get a list of each line in the file.
And then use a for loop to iterate over each line of contents.
At the end I put an elif to get "results" too, to match the expected outputs.

with open('file1.txt', "r") as f1:
    contents = f1.readlines()
    with open('output1.txt', "w+") as f2:
        for line in contents:
            if "comb" not in line:
                if "input" in line:
                    f2.write(line)
                elif "output" in line:
                    f2.write(line)
                elif "assign" in line:
                    f2.write(line)
                elif "result" in line:
                    f2.write(line)