FIRST, I DO THIS:
        dumps_path = '/public/dumps/public/'+languagecode+'wiki/latest/'+languagecode+'wiki-latest-page.sql.gz'
        wikilanguages_utils.check_dump(dumps_path, script_name)

        dump_in = gzip.open(dumps_path, 'r')
        iter = 0

        while True:
            iter+=1
            line = dump_in.readline()
            try: line = line.decode("utf-8")
            except UnicodeDecodeError:
                print ('error.')
                line = str(line)

            if line == '':
                i+=1
                if i==3: break
            else: i=0

            if wikilanguages_utils.is_insert(line):
                values = wikilanguages_utils.get_values(line)
                if wikilanguages_utils.values_sanity_check(values): rows = wikilanguages_utils.parse_values(values)

                for row in rows:
                    page_id = int(row[0])
                    page_namespace = int(row[1])
                    cat_title = str(row[2])

                    if page_namespace != 14: continue
                    category_page_ids_page_titles[page_id]=cat_title

                    category_links_cat_cat[cat_title]=set()
                    category_links_cat_art[cat_title]=set()

            if iter % 10000 == 0:
                print (str(iter)+' categories loaded.')

        print (str(datetime.timedelta(seconds=time.time() - functionstartTime)))
        print (len(category_links_cat_cat))
        print ('all categories loaded')


THEN, I DO THIS:
        dumps_path = '/public/dumps/public/'+languagecode+'wiki/latest/'+languagecode+'wiki-latest-categorylinks.sql.gz'
        wikilanguages_utils.check_dump(dumps_path, script_name)
        dump_in = gzip.open(dumps_path, 'r')

        a = 0
        c = 0
        iter = 0
        while True:
            iter+=1
            line = dump_in.readline()
            try: line = line.decode("utf-8")
            except UnicodeDecodeError:
                print ('error.')
                line = str(line)

            if line == '':
                i+=1
                if i==3: break
            else: i=0

            if wikilanguages_utils.is_insert(line):
                values = wikilanguages_utils.get_values(line)
                if wikilanguages_utils.values_sanity_check(values): rows = wikilanguages_utils.parse_values(values)

                for row in rows:

                    try:
                        page_id = int(row[0])
                        cat_title = str(row[1].strip("'"))
                    except:
                        continue


                    if cat_title not in category_links_cat_cat:
                        continue

                    if page_id in category_page_ids_page_titles: # is this a category
                        c += 1
                        category_links_cat_cat[cat_title].add(category_page_ids_page_titles[page_id])
                    else: # this is an article
                        a += 1
                        category_links_cat_art[cat_title].add(page_id)