在不知道序列长度的情况下，在Python中展开多个赋值

The textbook examples of multiple unpacking assignment are something like:

多重拆包作业的教科书示例如下:

import numpy as NP
M = NP.arange(5)
a, b, c, d, e = M
# so of course, a = 0, b = 1, etc.

M = NP.arange(20).reshape(5, 4)     # numpy 5x4 array
a, b, c, d, e = M
# here, a = M[0,:], b = M[1,:], etc. (ie, a single row of M is assigned each to a through e)

(My Q is not numpy specfic; indeed, i would prefer a pure python solution.)

(我的Q并不麻木;实际上，我更喜欢纯python解决方案。

W/r/t the piece of code i'm looking at now, i see two complications on that straightforward scenario:

W/r/t我现在看到的这段代码，我看到了两个复杂的情况:

i usually won't know the shape of M; and
我通常不知道M的形状;和
i want to unpack a certain number of items (definitely less than all items) and i want to put the remainder into a single container
我想要解压缩一定数量的项(绝对小于所有项)，我想把剩余的项放入一个容器中。

so back to the 5x4 array above, what i would very much like to be able to do is, for instance, assign the first three rows of M to a, b, and c respectively (exactly as above) and the rest of the rows (i have no idea how many there will be, just some positive integer) to a single container, all_the_rest = [].

回到上面的5 x4数组中,我很想能够做的是,例如,分配的前三行M a,b和c分别(如上图),其余的行(我不知道有多少会有,只是一些正整数)到一个容器,all_the_rest =[]。

I'm not sure if i have explained this clearly; in any event, if i get feedback i'll promptly edit my Question.

我不确定我是否解释得很清楚;无论如何，如果我得到反馈，我会立即修改我的问题。

2 个解决方案

#1

Python 3.x can do this easily:

Python 3。x可以很容易地做到这一点:

a, b, *c = someseq

Python 2.x needs a bit more work:

Python 2。x需要多做一点工作:

(a, b), c = someseq[:2], someseq[2:]

2 个解决方案

#1

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