Python Keyword Generator without Export

import time

keyword_list1 = ['create', 'make', 'build', 'develop', 'start', 'design']
keyword_list2 = ['taxi', 'cab', 'uber', 'lyft']
keyword_list3 = ['app', 'application']
keyword_list4 = []
keyword_list5 = []


marker_keyword_list = []
words_lists = 0

if len(keyword_list1) > 0:
    words_lists += 1
    if len(keyword_list2) > 0:
        words_lists += 1
        if len(keyword_list3) > 0:
            words_lists += 1
            if len(keyword_list4) > 0:
                words_lists += 1
                if len(keyword_list5) > 0:
                    words_lists += 1
    else:
        print('keywords_list2 должен быть заполнен!')
else:
    print('keyword_list1 должен быть заполнен!')


# перебираем варианты, прогоняя по вложенным циклам
if words_lists == 2:
    for i in keyword_list1:
        for k in keyword_list2:
            marker_keyword_list.append(i + ' ' + k)
elif words_lists == 3:
    for i in keyword_list1:
        for j in keyword_list2:
            for k in keyword_list3:
                marker_keyword_list.append(i + ' ' + j + ' ' + k)
elif words_lists == 4:
    for i in keyword_list1:
        for j in keyword_list2:
            for k in keyword_list3:
                for m in keyword_list4:
                    marker_keyword_list.append(i + ' ' + j + ' ' + k + ' ' + m)
elif words_lists == 5:
    for i in keyword_list1:
        for j in keyword_list2:
            for k in keyword_list3:
                for m in keyword_list4:
                    for n in keyword_list5:
                        marker_keyword_list.append(i + ' ' + j + ' ' + k + ' ' + m + ' ' + n)


for i in marker_keyword_list:
    print(i)