def are_in_file(file_path, strs_to_find):
    """Returns true if every string in the given strs_to_find array is found in
    at least one line in the given file. In particular, returns true if
    strs_to_find is empty. Note that the strs_to_find parameter is mutated."""
    infile = open(file_path)

    for line in infile:
        if len(strs_to_find) == 0:
            return True

        index = 0
        while index < len(strs_to_find):
            if strs_to_find[index] in line:
                del strs_to_find[index]
            else:
                index = index + 1

    return len(strs_to_find) == 0