file_readme = './../readme.md' with open(file_readme, 'r') as read_readme: content_readme = read_readme.readlines() def content_about(): content_about_errors_nums = [] content_about_line = 'Content about:' for j, i in enumerate(content_readme): if content_about_line in i: if i[-2] != '\\': content_about_errors_nums.append(j) return content_about_errors_nums content_about_errors_nums = content_about()