向组合添加列表

Question

我有一个列表A，包含8个值。我喜欢先做组合，然后在列表B中为每个组合再加两个点。这是我的代码：

def combination(arr, r):
return list(itertools.combinations(arr, r))
A = [[0.0, 0.0, 0.0], [0.0, 0.5, 0.0], [0.5, 0.0, 0.5], [0.5, 0.5, 0.5], [0.0, 0.25, 0.0], [0.0, 0.7499999819999985, 0.0], [0.5, 0.25, 0.5], [0.5, 0.7499999819999985, 0.5]]
B = [[0.4950293947410103, 0.5021785267638279, 0.4935703740156043], [1, 1, 1]]
n = 1 #can be change
com = combination(A, n)
for item in com:
item.extend(B)
print(item)

但我有一个错误：

AttributeError: 'tuple' object has no attribute 'extend'

预期结果：

[[0.0, 0.0, 0.0], [0.4950293947410103, 0.5021785267638279, 0.4935703740156043], [1, 1, 1]]
[[0.0, 0.5, 0.0], [0.4950293947410103, 0.5021785267638279, 0.4935703740156043], [1, 1, 1]]
[[0.5, 0.0, 0.5], [0.4950293947410103, 0.5021785267638279, 0.4935703740156043], [1, 1, 1]]
[[0.5, 0.5, 0.5], [0.4950293947410103, 0.5021785267638279, 0.4935703740156043], [1, 1, 1]]
[[0.0, 0.25, 0.0], [0.4950293947410103, 0.5021785267638279, 0.4935703740156043], [1, 1, 1]]
[[0.0, 0.7499999819999985, 0.0], [0.4950293947410103, 0.5021785267638279, 0.4935703740156043], [1, 1, 1]]
[[0.5, 0.25, 0.5], [0.4950293947410103, 0.5021785267638279, 0.4935703740156043], [1, 1, 1]]
[[0.5, 0.7499999819999985, 0.5], [0.4950293947410103, 0.5021785267638279, 0.4935703740156043], [1, 1, 1]]

Answer 1

类型tuple(按组合返回(是不可变的，您可以使用list并用item和B填充它

com = combination(A, n)
com = [[*item, *B] for item in com]

---

或从组合返回列表列表

def combination(arr, r):
return [list(c) for c in itertools.combinations(arr, r)]
# ...
for item in com:
item.extend(B)

Answer 2

您还可以使用map函数来获取列表。

map((函数将给定函数应用于给定可迭代(在您的案例列表中(的每个项后，返回结果的map对象(它是迭代器(

而不是：

com = combination(A, n)

用途：

com = map(list, combination(A, n))