for entry in list: if entry not in found: found.append(entry) keep.append(entry) return keep with open('boroughs.csv') as f: rows = csv.reader(f, delimiter=',') for row in rows: thiszip = Zipcode(row[0]) rowentry = row[1] if (rowentry.lower() == borough.name): borough.addZipcode(thiszip.number) borough.zipcodes = makeunique(borough.zipcodes) with open('zipCodes.csv') as f: rows = csv.reader(f, delimiter=',') rows.next() for row in rows: if (row[10] != ''): rowzip = row[1] rowpop = float(row[10].strip()) for line in borough.zipcodes: if (int(rowzip) == int(line)): borough.addPopulation(rowpop) borough.findAverage() print borough.average