打印两个输出的列表，没有重复或类似的二重奏

Question

我已经为我的脚本寻找了一个解决方案，但没有成功。

我正在尝试打印给定列表中所有可能的二重奏。除了不打印重复项，例如 (a, a)。并且不打印两次组合例如如果（a，b）已经打印，那么（b，a）将不会被打印。

FLAVORS = [
    "Banana",
    "Chocolate",
    "Lemon",
    "Pistachio",
    "Raspberry",
    "Strawberry",
    "Vanilla",
]

for i in FLAVORS:
    for j in FLAVORS:
        if (i != j) :
            print(i, j, sep=", ")

我设法不打印重复项，例如 (a, a)。但是，我被困在如何只打印一次组合上，所以如果 (a, b) 被打印，则 (b, a) 不会被打印。

Answer 1

您可以使用itertools.combinations

import itertools
FLAVORS = [
    "Banana",
    "Chocolate",
    "Lemon",
    "Pistachio",
    "Raspberry",
    "Strawberry",
    "Vanilla",
]
x=list(itertools.combinations(FLAVORS,2))
print(x)

Answer 2

类似的东西？

FLAVORS = [
    "Banana",
    "Chocolate",
    "Lemon",
]
n = len(FLAVORS)

for i in range(n):
    for j in range(i+1, n):
        print(FLAVORS[i], FLAVORS[j], sep=", ")

Banana, Chocolate
Banana, Lemon
Chocolate, Lemon

Answer 3

解决办法

FLAVORS = [
    "Banana",
    "Chocolate",
    "Lemon",
    "Pistachio",
    "Raspberry",
    "Strawberry",
    "Vanilla",
]

for i in range(len(FLAVORS)):
    for j in range(i+1,len(FLAVORS)):
        print(FLAVORS[i],FLAVORS[j],sep=",")