如何列表中的每个元素有两个清单合并到其他列表

Question

假设：

['a', 'b', 'c'], ['d', 'e', 'f'] 

我要的是：

'ad','ae','af','bd','be','bf','cd','ce','cf' 


first_list = ['a', 'b', 'c'] 
second_list = ['d', 'e', 'f'] 
combined_list = [] 
for i in first_list: 
    for j in second_list: 
     combined_list.append(i + j) 
print(combined_list) 

我的问题是，如果不仅有两份名单，如何改进代码？ 例如，

first_list = ['a', 'b', 'c'] 
second_list = ['d', 'e', 'f'] 
third_list = ['g','h','q'] 
print ['adg','adh','adq','aeg','aeh',.......] 

家伙，还有什么可推广的方式来表演n lists..I意思是，如果有什么有超过三个列表？

Answer 1

我还没有测试过，但这应该工作。

first_list = ['a', 'b', 'c'] 
second_list = ['d', 'e', 'f'] 
third_list = ['g','h','q'] 
combined_list = [] 
for i in first_list: 
    for j in second_list: 
     for k in third_list: 
      combined_list.append(i + j + k) 
print(combined_list) 

Answer 2

这被称为笛卡尔产品。

import itertools 

first_list = ['a', 'b', 'c'] 
second_list = ['d', 'e', 'f'] 
third_list = ['g','h','q'] 
lists = [first_list, second_list, third_list] 

cartesian_product = [''.join(x) for x in itertools.product(*lists)] 

print(cartesian_product) 

输出：

['adg', 'adh', 'adq', 'aeg', 'aeh', 'aeq', 'afg', 'afh', 'afq', 
'bdg', 'bdh', 'bdq', 'beg', 'beh', 'beq', 'bfg', 'bfh', 'bfq', 
'cdg', 'cdh', 'cdq', 'ceg', 'ceh', 'ceq', 'cfg', 'cfh', 'cfq'] 

你可以在线试用，here。

这里是一个笛卡尔生产函数，你可以尝试here的示例实现。

def cartesian_product(*lists): 
    if not lists: # base case 
     return [[]] 
    else: 
     this_list = lists[0] 
     remaining_lists = lists[1:] 
     return [ 
      [x] + p 
      for x in this_list 
       for p in cartesian_product(*remaining_lists) 
     ]