I started playing with Python and programming in general like 3 weeks ago so be gentle What i try to do is convert text files the way i want them to be, the text files have same pattern but the words i want to replace are unknown. So the program must first find them, set a pattern and then replace them to words i want. For example: xxxxx xxxxx Line3 - word - xxxx xxxx xxxxx xxxx word word xxxx word Legend: xxxxx = template words, present in every file word = random word, our target I am able to localize first apperance of the word because it appears always in the same place of the file, from then it appears randomly. MY code: f1 = open('test.txt', 'r') f2 = open('file2.txt', 'w') pattern = '' for line in f1.readlines(): if line.startswith('Seat 1'): line = line.split(' ', 3) pattern = line[2] line = ' '.join(line) f2.write(line) elif pattern in line.strip(): f2.write(line.replace(pattern, 'NewWord')) else: f2.write(line) f1.close() f2.close() This code doesnt work, whats wrong ? Continue reading...