<p>可以使用递归生成器函数:</p>
<pre><code>def combos(d, c = []):
if not d:
yield c
else:
for i in filter(lambda x:x not in c, d[0]):
yield from combos(d[1:], c+[i])
print(list(combos([crust,topping1,topping2,sauce1,sauce2])))
</code></pre>
<p>输出:</p>
<pre><code>[['Thin Crust', 'Bacon', 'Pepperoni', 'Tomato', 'BBQ'], ['Thin Crust', 'Bacon', 'Pepperoni', 'Tomato', 'Ranch'], ['Thin Crust', 'Bacon', 'Pepperoni', 'BBQ', 'Tomato'], ['Thin Crust', 'Bacon', 'Pepperoni', 'BBQ', 'Ranch'], ['Thin Crust', 'Bacon', 'Pepperoni', 'Ranch', 'Tomato'], ['Thin Crust', 'Bacon', 'Pepperoni', 'Ranch', 'BBQ'], ['Thin Crust', 'Bacon', 'Steak', 'Tomato', 'BBQ'], ['Thin Crust', 'Bacon', 'Steak', 'Tomato', 'Ranch'], ['Thin Crust', 'Bacon', 'Steak', 'BBQ', 'Tomato'], ['Thin Crust', 'Bacon', 'Steak', 'BBQ', 'Ranch'], ['Thin Crust', 'Bacon', 'Steak', 'Ranch', 'Tomato'], ['Thin Crust', 'Bacon', 'Steak', 'Ranch', 'BBQ'], ['Thin Crust', 'Pepperoni', 'Bacon', 'Tomato', 'BBQ'], ['Thin Crust', 'Pepperoni', 'Bacon', 'Tomato', 'Ranch'], ['Thin Crust', 'Pepperoni', 'Bacon', 'BBQ', 'Tomato'], ['Thin Crust', 'Pepperoni', 'Bacon', 'BBQ', 'Ranch'], ['Thin Crust', 'Pepperoni', 'Bacon', 'Ranch', 'Tomato'], ['Thin Crust', 'Pepperoni', 'Bacon', 'Ranch', 'BBQ'], ['Thin Crust', 'Pepperoni', 'Steak', 'Tomato', 'BBQ'], ['Thin Crust', 'Pepperoni', 'Steak', 'Tomato', 'Ranch'], ['Thin Crust', 'Pepperoni', 'Steak', 'BBQ', 'Tomato'], ['Thin Crust', 'Pepperoni', 'Steak', 'BBQ', 'Ranch'], ['Thin Crust', 'Pepperoni', 'Steak', 'Ranch', 'Tomato'], ['Thin Crust', 'Pepperoni', 'Steak', 'Ranch', 'BBQ'], ['Thin Crust', 'Steak', 'Bacon', 'Tomato', 'BBQ'], ['Thin Crust', 'Steak', 'Bacon', 'Tomato', 'Ranch'], ['Thin Crust', 'Steak', 'Bacon', 'BBQ', 'Tomato'], ['Thin Crust', 'Steak', 'Bacon', 'BBQ', 'Ranch'], ['Thin Crust', 'Steak', 'Bacon', 'Ranch', 'Tomato'], ['Thin Crust', 'Steak', 'Bacon', 'Ranch', 'BBQ'], ['Thin Crust', 'Steak', 'Pepperoni', 'Tomato', 'BBQ'], ['Thin Crust', 'Steak', 'Pepperoni', 'Tomato', 'Ranch'], ['Thin Crust', 'Steak', 'Pepperoni', 'BBQ', 'Tomato'], ['Thin Crust', 'Steak', 'Pepperoni', 'BBQ', 'Ranch'], ['Thin Crust', 'Steak', 'Pepperoni', 'Ranch', 'Tomato'], ['Thin Crust', 'Steak', 'Pepperoni', 'Ranch', 'BBQ'], ['Hand Tossed', 'Bacon', 'Pepperoni', 'Tomato', 'BBQ'], ['Hand Tossed', 'Bacon', 'Pepperoni', 'Tomato', 'Ranch'], ['Hand Tossed', 'Bacon', 'Pepperoni', 'BBQ', 'Tomato'], ['Hand Tossed', 'Bacon', 'Pepperoni', 'BBQ', 'Ranch'], ['Hand Tossed', 'Bacon', 'Pepperoni', 'Ranch', 'Tomato'], ['Hand Tossed', 'Bacon', 'Pepperoni', 'Ranch', 'BBQ'], ['Hand Tossed', 'Bacon', 'Steak', 'Tomato', 'BBQ'], ['Hand Tossed', 'Bacon', 'Steak', 'Tomato', 'Ranch'], ['Hand Tossed', 'Bacon', 'Steak', 'BBQ', 'Tomato'], ['Hand Tossed', 'Bacon', 'Steak', 'BBQ', 'Ranch'], ['Hand Tossed', 'Bacon', 'Steak', 'Ranch', 'Tomato'], ['Hand Tossed', 'Bacon', 'Steak', 'Ranch', 'BBQ'], ['Hand Tossed', 'Pepperoni', 'Bacon', 'Tomato', 'BBQ'], ['Hand Tossed', 'Pepperoni', 'Bacon', 'Tomato', 'Ranch'], ['Hand Tossed', 'Pepperoni', 'Bacon', 'BBQ', 'Tomato'], ['Hand Tossed', 'Pepperoni', 'Bacon', 'BBQ', 'Ranch'], ['Hand Tossed', 'Pepperoni', 'Bacon', 'Ranch', 'Tomato'], ['Hand Tossed', 'Pepperoni', 'Bacon', 'Ranch', 'BBQ'], ['Hand Tossed', 'Pepperoni', 'Steak', 'Tomato', 'BBQ'], ['Hand Tossed', 'Pepperoni', 'Steak', 'Tomato', 'Ranch'], ['Hand Tossed', 'Pepperoni', 'Steak', 'BBQ', 'Tomato'], ['Hand Tossed', 'Pepperoni', 'Steak', 'BBQ', 'Ranch'], ['Hand Tossed', 'Pepperoni', 'Steak', 'Ranch', 'Tomato'], ['Hand Tossed', 'Pepperoni', 'Steak', 'Ranch', 'BBQ'], ['Hand Tossed', 'Steak', 'Bacon', 'Tomato', 'BBQ'], ['Hand Tossed', 'Steak', 'Bacon', 'Tomato', 'Ranch'], ['Hand Tossed', 'Steak', 'Bacon', 'BBQ', 'Tomato'], ['Hand Tossed', 'Steak', 'Bacon', 'BBQ', 'Ranch'], ['Hand Tossed', 'Steak', 'Bacon', 'Ranch', 'Tomato'], ['Hand Tossed', 'Steak', 'Bacon', 'Ranch', 'BBQ'], ['Hand Tossed', 'Steak', 'Pepperoni', 'Tomato', 'BBQ'], ['Hand Tossed', 'Steak', 'Pepperoni', 'Tomato', 'Ranch'], ['Hand Tossed', 'Steak', 'Pepperoni', 'BBQ', 'Tomato'], ['Hand Tossed', 'Steak', 'Pepperoni', 'BBQ', 'Ranch'], ['Hand Tossed', 'Steak', 'Pepperoni', 'Ranch', 'Tomato'], ['Hand Tossed', 'Steak', 'Pepperoni', 'Ranch', 'BBQ']]
</code></pre>
<p>您还可以使用<code>itertools.product</code>预先生成所有组合,然后使用重复值筛选结果:</p>
<pre><code>import itertools as it
r = [i for i in it.product(crust,topping1,topping2,sauce1,sauce2) if len(i) == len(set(i))]
</code></pre>