英文:
How can I change the first element of a list?
问题
我有一个元素列表：
[[0, 0, 0], [0, 0, 1], [0, 0, 2], [0, 1, 0], [0, 1, 1], [0, 1, 2], [0, 2, 0], [0, 2, 1], [0, 2, 2]]
我想按以下方式增加它：
[[1, 0, 0], [1, 0, 1], [1, 0, 2], [1, 1, 0], [1, 1, 1].................] 然后是2：
[[2, 0, 0], [2, 0, 1], [2, 0, 2], [2, 1, 0], [2, 1, 1].................] 以此类推，直到5。
我不想硬编码，所以我尝试使用itertools，但我只能达到2，像这样：
first2 = list(map(list, itertools.product(list(range(3)), repeat = 3)))
非常感谢任何帮助。
英文:
I have this list of elements:
[[0, 0, 0], [0, 0, 1], [0, 0, 2], [0, 1, 0], [0, 1, 1], [0, 1, 2], [0, 2, 0], [0, 2, 1], [0, 2, 2]]
and I would like to increase it like this:
[[1, 0, 0], [1, 0, 1], [1, 0, 2], [1, 1, 0], [1, 1, 1].................] then with 2:
[[2, 0, 0], [2, 0, 1], [2, 0, 2], [2, 1, 0], [2, 1, 1].................] and so on until 5.
I dont want to hard code so I was trying itertools but I could only reach up to 2 like this:
first2 = list(map(list, itertools.product(list(range(3)), repeat = 3)))
Any help is highly appreciated.
答案1
得分: 1
使用itertools.product()函数创建第二个和第三个元素，并使用外部循环将0到5添加到它们之前。
import itertools
result = []
for i in range(6):
result.extend([i] + list(x) for x in itertools.product(range(3), repeat=2))
英文:
Use itertools.product() to create the 2nd and 3rd elements, and an outer loop to prepend 0 through 5 to them.
result = []
for i in range(6):
result.extend([i] + list(x) for x in itertools.product(range(3), repeat = 2))
答案2
得分: 0
我不明白你所说的“不想硬编码”的意思。
你不能像这样做吗？
for _ in range(5):
for item in mylist:
item[0] += 1
英文:
I don't understand what you mean by "dont want to hard code".
Can't you just do something like this?
for _ in range(5):
for item in mylist:
item[0] += 1
答案3
得分: 0
尝试：
lst = [
[0, 0, 0],
[0, 0, 1],
[0, 0, 2],
[0, 1, 0],
[0, 1, 1],
[0, 1, 2],
[0, 2, 0],
[0, 2, 1],
[0, 2, 2],
]
out = []
for i in range(1, 6):
out.append([[i, *subl[1:]] for subl in lst])
print(out)
输出结果：
[
[
[1, 0, 0],
[1, 0, 1],
[1, 0, 2],
[1, 1, 0],
[1, 1, 1],
[1, 1, 2],
[1, 2, 0],
[1, 2, 1],
[1, 2, 2],
],
[
[2, 0, 0],
[2, 0, 1],
[2, 0, 2],
...
一行代码：
out = [[[i, *subl[1:]] for subl in lst] for i in range(1, 6)]
print(out)
英文:
Try:
lst = [
[0, 0, 0],
[0, 0, 1],
[0, 0, 2],
[0, 1, 0],
[0, 1, 1],
[0, 1, 2],
[0, 2, 0],
[0, 2, 1],
[0, 2, 2],
]
out = []
for i in range(1, 6):
out.append([[i, *subl[1:]] for subl in lst])
print(out)
Prints:
[
[
[1, 0, 0],
[1, 0, 1],
[1, 0, 2],
[1, 1, 0],
[1, 1, 1],
[1, 1, 2],
[1, 2, 0],
[1, 2, 1],
[1, 2, 2],
],
[
[2, 0, 0],
[2, 0, 1],
[2, 0, 2],
...
One-liner:
out = [[[i, *subl[1:]] for subl in lst] for i in range(1, 6)]
print(out)
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