python将列表附加到元组

I have following tuple:

我有以下元组：

vertices = ([0,0],[0,0],[0,0]);

And on each loop I want to append the following list:

在每个循环中，我想附加以下列表：

[x, y]

How should I approach it?

我该怎么办呢？

5 个解决方案

#1

You can't append a list to a tuple because tuples are "immutable" (they can't be changed). It is however easy to append a tuple to a list:

您不能将列表附加到元组，因为元组是“不可变的”（它们不能更改）。然而，将元组附加到列表很容易：

vertices = [(0, 0), (0, 0), (0, 0)]
for x in range(10):
    vertices.append((x, y))

You can add tuples together to create a new, longer tuple, but that strongly goes against the purpose of tuples, and will slow down as the number of elements gets larger. Using a list in this case is preferred.

您可以将元组一起添加以创建一个新的，更长的元组，但这很有可能违背元组的目的，并且随着元素数量的增加而减慢。在这种情况下使用列表是首选。

#2

You can't modify a tuple. You'll either need to replace the tuple with a new one containing the additional vertex, or change it to a list. A list is simply a modifiable tuple.

你不能修改元组。您需要使用包含附加顶点的新元组替换元组，或将其更改为列表。列表只是一个可修改的元组。

vertices = [[0,0],[0,0],[0,0]]

for ...:
    vertices.append([x, y])

#3

You can concatenate two tuples:

您可以连接两个元组：

>>> vertices = ([0,0],[0,0],[0,0])
>>> lst = [10, 20]
>>> vertices = vertices + tuple([lst])
>>> vertices
([0, 0], [0, 0], [0, 0], [10, 20])

#4

You probably want a list, as mentioned above. But if you really need a tuple, you can create a new tuple by concatenating tuples:

如上所述，您可能需要一个列表。但是如果你真的需要一个元组，你可以通过连接元组来创建一个新的元组：

vertices = ([0,0],[0,0],[0,0])
for x in (1, 2):
    for y in (3, 4):
        vertices += ([x,y],)

Alternatively, and for more efficiency, use a list while you're building the tuple and convert it at the end:

或者，为了提高效率，在构建元组时使用列表并在结尾处转换它：

vertices = ([0,0],[0,0],[0,0])
#...
vlist = list(vertices)
for x in (1, 2):
    for y in (3, 4):
        vlist.append([x, y])
vertices = tuple(vlist)

At the end of either one, vertices is:

在任何一个的末尾，顶点是：

([0, 0], [0, 0], [0, 0], [1, 3], [1, 4], [2, 3], [2, 4])

#5

Not sure I understand you, but if you want to append x,y to each vertex you can do something like :

不确定我理解你，但是如果你想将x，y附加到每个顶点，你可以做类似的事情：

vertices = ([0,0],[0,0],[0,0])

for v in vertices:
    v[0] += x
    v[1] += y

#1