To compare two files and update the orginal
f = open("C:\\temp\old.csv", "r") lines = f.read() f.close() f2 = open("C:\\temp\\new.csv", "r") cnt = 0 for var in f2.readlines(): f = open("C:\\temp\old.csv", "a") if var not in lines: cnt = cnt +1 print(var) f.write(var) f.close() f2.close() print(cnt, " new transactions")