如何在使用python选择不同列的循环中增加i

我想知道如何在Python3中创建一个循环来增加I，j，k的值。。。对于特定的应用程序

我需要选择不同的列，但不能自己选择。假设我的dataframe有7列。我将在下面举个例子

这样做的目的是创建如下选择：

[0, 1]
[0, 2]
[0, 3]
[0, 4]
[0, 5]
[0, 6]
 ...
[0, 3, 6]
[0, 3, 7]
[0, 4, 5]
[0, 4, 6]
[0, 4, 7]
[0, 5, 6]
[0, 5, 7]
[0, 6, 7]
[0, 1, 2, 3]
[0, 1, 2, 4]
[0, 1, 2, 5]
[0, 1, 2, 6]
[0, 1, 2, 7]
[0, 1, 2, 3, 4]
[0, 1, 2, 3, 5]
[0, 1, 2, 3, 6]
[0, 1, 2, 3, 7]
 ...
[0, 1, 2, 3, 4, 7]
[0, 1, 2, 3, 4, 5, 6]
[0, 1, 2, 3, 4, 5, 7]
[0, 1, 2, 3, 4, 5, 8]
[0, 1, 2, 3, 4, 5, 6, 7]

在一些回复之后，我可以创建以下代码：

from itertools import combinations 
numbers = [] 
A = [0,1,2,3,4,5,6,7] 
for i in range(8): 
   for combo in combinations(A, i+2): 
      numbrs.append(combo)

输出为：

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

如何使用这些数字作为iloc迭代器的索引

例如，生成的数字必须替换代码：

df.iloc[:,[i, j, k, ...]]

---

然后我将能够在列之间进行交互

您可以使用

itertools.compositions

和

itertools.chain

解决此问题：

import itertools as it

list(it.chain(*(it.combinations(range(8), r) for r in range(2, 9))))

或者，如果您愿意，可以使用列表理解：

[x for r in range(2, 9) for x in it.combinations(range(8), r)] 

这将产生以下输出：

[(0, 1),
 (0, 2),
 (0, 3),
 (0, 4),
 (0, 5),
 (0, 6),
 (0, 7),
 (1, 2),
 (1, 3),
 (1, 4),
 (1, 5),
 (1, 6),
 (1, 7),
 (2, 3),
 (2, 4),
 (2, 5),
 (2, 6),
 (2, 7),
 (3, 4),
 (3, 5),
 (3, 6),
 (3, 7),
 (4, 5),
 (4, 6),
 (4, 7),
 (5, 6),
 (5, 7),
 (6, 7),
 (0, 1, 2),
 (0, 1, 3),
 (0, 1, 4),
 (0, 1, 5),
 (0, 1, 6),
 (0, 1, 7),
 (0, 2, 3),
 (0, 2, 4),
 (0, 2, 5),
 (0, 2, 6),
 (0, 2, 7),
 (0, 3, 4),
 (0, 3, 5),
 (0, 3, 6),
 (0, 3, 7),
 (0, 4, 5),
 (0, 4, 6),
 (0, 4, 7),
 (0, 5, 6),
 (0, 5, 7),
 (0, 6, 7),
 (1, 2, 3),
 (1, 2, 4),
 (1, 2, 5),
 (1, 2, 6),
 (1, 2, 7),
 (1, 3, 4),
 (1, 3, 5),
 (1, 3, 6),
 (1, 3, 7),
 (1, 4, 5),
 (1, 4, 6),
 (1, 4, 7),
 (1, 5, 6),
 (1, 5, 7),
 (1, 6, 7),
 (2, 3, 4),
 (2, 3, 5),
 (2, 3, 6),
 (2, 3, 7),
 (2, 4, 5),
 (2, 4, 6),
 (2, 4, 7),
 (2, 5, 6),
 (2, 5, 7),
 (2, 6, 7),
 (3, 4, 5),
 (3, 4, 6),
 (3, 4, 7),
 (3, 5, 6),
 (3, 5, 7),
 (3, 6, 7),
 (4, 5, 6),
 (4, 5, 7),
 (4, 6, 7),
 (5, 6, 7),
 (0, 1, 2, 3),
 (0, 1, 2, 4),
 (0, 1, 2, 5),
 (0, 1, 2, 6),
 (0, 1, 2, 7),
 (0, 1, 3, 4),
 (0, 1, 3, 5),
 (0, 1, 3, 6),
 (0, 1, 3, 7),
 (0, 1, 4, 5),
 (0, 1, 4, 6),
 (0, 1, 4, 7),
 (0, 1, 5, 6),
 (0, 1, 5, 7),
 (0, 1, 6, 7),
 (0, 2, 3, 4),
 (0, 2, 3, 5),
 (0, 2, 3, 6),
 (0, 2, 3, 7),
 (0, 2, 4, 5),
 (0, 2, 4, 6),
 (0, 2, 4, 7),
 (0, 2, 5, 6),
 (0, 2, 5, 7),
 (0, 2, 6, 7),
 (0, 3, 4, 5),
 (0, 3, 4, 6),
 (0, 3, 4, 7),
 (0, 3, 5, 6),
 (0, 3, 5, 7),
 (0, 3, 6, 7),
 (0, 4, 5, 6),
 (0, 4, 5, 7),
 (0, 4, 6, 7),
 (0, 5, 6, 7),
 (1, 2, 3, 4),
 (1, 2, 3, 5),
 (1, 2, 3, 6),
 (1, 2, 3, 7),
 (1, 2, 4, 5),
 (1, 2, 4, 6),
 (1, 2, 4, 7),
 (1, 2, 5, 6),
 (1, 2, 5, 7),
 (1, 2, 6, 7),
 (1, 3, 4, 5),
 (1, 3, 4, 6),
 (1, 3, 4, 7),
 (1, 3, 5, 6),
 (1, 3, 5, 7),
 (1, 3, 6, 7),
 (1, 4, 5, 6),
 (1, 4, 5, 7),
 (1, 4, 6, 7),
 (1, 5, 6, 7),
 (2, 3, 4, 5),
 (2, 3, 4, 6),
 (2, 3, 4, 7),
 (2, 3, 5, 6),
 (2, 3, 5, 7),
 (2, 3, 6, 7),
 (2, 4, 5, 6),
 (2, 4, 5, 7),
 (2, 4, 6, 7),
 (2, 5, 6, 7),
 (3, 4, 5, 6),
 (3, 4, 5, 7),
 (3, 4, 6, 7),
 (3, 5, 6, 7),
 (4, 5, 6, 7),
 (0, 1, 2, 3, 4),
 (0, 1, 2, 3, 5),
 (0, 1, 2, 3, 6),
 (0, 1, 2, 3, 7),
 (0, 1, 2, 4, 5),
 (0, 1, 2, 4, 6),
 (0, 1, 2, 4, 7),
 (0, 1, 2, 5, 6),
 (0, 1, 2, 5, 7),
 (0, 1, 2, 6, 7),
 (0, 1, 3, 4, 5),
 (0, 1, 3, 4, 6),
 (0, 1, 3, 4, 7),
 (0, 1, 3, 5, 6),
 (0, 1, 3, 5, 7),
 (0, 1, 3, 6, 7),
 (0, 1, 4, 5, 6),
 (0, 1, 4, 5, 7),
 (0, 1, 4, 6, 7),
 (0, 1, 5, 6, 7),
 (0, 2, 3, 4, 5),
 (0, 2, 3, 4, 6),
 (0, 2, 3, 4, 7),
 (0, 2, 3, 5, 6),
 (0, 2, 3, 5, 7),
 (0, 2, 3, 6, 7),
 (0, 2, 4, 5, 6),
 (0, 2, 4, 5, 7),
 (0, 2, 4, 6, 7),
 (0, 2, 5, 6, 7),
 (0, 3, 4, 5, 6),
 (0, 3, 4, 5, 7),
 (0, 3, 4, 6, 7),
 (0, 3, 5, 6, 7),
 (0, 4, 5, 6, 7),
 (1, 2, 3, 4, 5),
 (1, 2, 3, 4, 6),
 (1, 2, 3, 4, 7),
 (1, 2, 3, 5, 6),
 (1, 2, 3, 5, 7),
 (1, 2, 3, 6, 7),
 (1, 2, 4, 5, 6),
 (1, 2, 4, 5, 7),
 (1, 2, 4, 6, 7),
 (1, 2, 5, 6, 7),
 (1, 3, 4, 5, 6),
 (1, 3, 4, 5, 7),
 (1, 3, 4, 6, 7),
 (1, 3, 5, 6, 7),
 (1, 4, 5, 6, 7),
 (2, 3, 4, 5, 6),
 (2, 3, 4, 5, 7),
 (2, 3, 4, 6, 7),
 (2, 3, 5, 6, 7),
 (2, 4, 5, 6, 7),
 (3, 4, 5, 6, 7),
 (0, 1, 2, 3, 4, 5),
 (0, 1, 2, 3, 4, 6),
 (0, 1, 2, 3, 4, 7),
 (0, 1, 2, 3, 5, 6),
 (0, 1, 2, 3, 5, 7),
 (0, 1, 2, 3, 6, 7),
 (0, 1, 2, 4, 5, 6),
 (0, 1, 2, 4, 5, 7),
 (0, 1, 2, 4, 6, 7),
 (0, 1, 2, 5, 6, 7),
 (0, 1, 3, 4, 5, 6),
 (0, 1, 3, 4, 5, 7),
 (0, 1, 3, 4, 6, 7),
 (0, 1, 3, 5, 6, 7),
 (0, 1, 4, 5, 6, 7),
 (0, 2, 3, 4, 5, 6),
 (0, 2, 3, 4, 5, 7),
 (0, 2, 3, 4, 6, 7),
 (0, 2, 3, 5, 6, 7),
 (0, 2, 4, 5, 6, 7),
 (0, 3, 4, 5, 6, 7),
 (1, 2, 3, 4, 5, 6),
 (1, 2, 3, 4, 5, 7),
 (1, 2, 3, 4, 6, 7),
 (1, 2, 3, 5, 6, 7),
 (1, 2, 4, 5, 6, 7),
 (1, 3, 4, 5, 6, 7),
 (2, 3, 4, 5, 6, 7),
 (0, 1, 2, 3, 4, 5, 6),
 (0, 1, 2, 3, 4, 5, 7),
 (0, 1, 2, 3, 4, 6, 7),
 (0, 1, 2, 3, 5, 6, 7),
 (0, 1, 2, 4, 5, 6, 7),
 (0, 1, 3, 4, 5, 6, 7),
 (0, 2, 3, 4, 5, 6, 7),
 (1, 2, 3, 4, 5, 6, 7),
 (0, 1, 2, 3, 4, 5, 6, 7)]

---

您可以使用

itertools.compositions

和

itertools.chain

解决此问题：

import itertools as it

list(it.chain(*(it.combinations(range(8), r) for r in range(2, 9))))

或者，如果您愿意，可以使用列表理解：

[x for r in range(2, 9) for x in it.combinations(range(8), r)] 

这将产生以下输出：

[(0, 1),
 (0, 2),
 (0, 3),
 (0, 4),
 (0, 5),
 (0, 6),
 (0, 7),
 (1, 2),
 (1, 3),
 (1, 4),
 (1, 5),
 (1, 6),
 (1, 7),
 (2, 3),
 (2, 4),
 (2, 5),
 (2, 6),
 (2, 7),
 (3, 4),
 (3, 5),
 (3, 6),
 (3, 7),
 (4, 5),
 (4, 6),
 (4, 7),
 (5, 6),
 (5, 7),
 (6, 7),
 (0, 1, 2),
 (0, 1, 3),
 (0, 1, 4),
 (0, 1, 5),
 (0, 1, 6),
 (0, 1, 7),
 (0, 2, 3),
 (0, 2, 4),
 (0, 2, 5),
 (0, 2, 6),
 (0, 2, 7),
 (0, 3, 4),
 (0, 3, 5),
 (0, 3, 6),
 (0, 3, 7),
 (0, 4, 5),
 (0, 4, 6),
 (0, 4, 7),
 (0, 5, 6),
 (0, 5, 7),
 (0, 6, 7),
 (1, 2, 3),
 (1, 2, 4),
 (1, 2, 5),
 (1, 2, 6),
 (1, 2, 7),
 (1, 3, 4),
 (1, 3, 5),
 (1, 3, 6),
 (1, 3, 7),
 (1, 4, 5),
 (1, 4, 6),
 (1, 4, 7),
 (1, 5, 6),
 (1, 5, 7),
 (1, 6, 7),
 (2, 3, 4),
 (2, 3, 5),
 (2, 3, 6),
 (2, 3, 7),
 (2, 4, 5),
 (2, 4, 6),
 (2, 4, 7),
 (2, 5, 6),
 (2, 5, 7),
 (2, 6, 7),
 (3, 4, 5),
 (3, 4, 6),
 (3, 4, 7),
 (3, 5, 6),
 (3, 5, 7),
 (3, 6, 7),
 (4, 5, 6),
 (4, 5, 7),
 (4, 6, 7),
 (5, 6, 7),
 (0, 1, 2, 3),
 (0, 1, 2, 4),
 (0, 1, 2, 5),
 (0, 1, 2, 6),
 (0, 1, 2, 7),
 (0, 1, 3, 4),
 (0, 1, 3, 5),
 (0, 1, 3, 6),
 (0, 1, 3, 7),
 (0, 1, 4, 5),
 (0, 1, 4, 6),
 (0, 1, 4, 7),
 (0, 1, 5, 6),
 (0, 1, 5, 7),
 (0, 1, 6, 7),
 (0, 2, 3, 4),
 (0, 2, 3, 5),
 (0, 2, 3, 6),
 (0, 2, 3, 7),
 (0, 2, 4, 5),
 (0, 2, 4, 6),
 (0, 2, 4, 7),
 (0, 2, 5, 6),
 (0, 2, 5, 7),
 (0, 2, 6, 7),
 (0, 3, 4, 5),
 (0, 3, 4, 6),
 (0, 3, 4, 7),
 (0, 3, 5, 6),
 (0, 3, 5, 7),
 (0, 3, 6, 7),
 (0, 4, 5, 6),
 (0, 4, 5, 7),
 (0, 4, 6, 7),
 (0, 5, 6, 7),
 (1, 2, 3, 4),
 (1, 2, 3, 5),
 (1, 2, 3, 6),
 (1, 2, 3, 7),
 (1, 2, 4, 5),
 (1, 2, 4, 6),
 (1, 2, 4, 7),
 (1, 2, 5, 6),
 (1, 2, 5, 7),
 (1, 2, 6, 7),
 (1, 3, 4, 5),
 (1, 3, 4, 6),
 (1, 3, 4, 7),
 (1, 3, 5, 6),
 (1, 3, 5, 7),
 (1, 3, 6, 7),
 (1, 4, 5, 6),
 (1, 4, 5, 7),
 (1, 4, 6, 7),
 (1, 5, 6, 7),
 (2, 3, 4, 5),
 (2, 3, 4, 6),
 (2, 3, 4, 7),
 (2, 3, 5, 6),
 (2, 3, 5, 7),
 (2, 3, 6, 7),
 (2, 4, 5, 6),
 (2, 4, 5, 7),
 (2, 4, 6, 7),
 (2, 5, 6, 7),
 (3, 4, 5, 6),
 (3, 4, 5, 7),
 (3, 4, 6, 7),
 (3, 5, 6, 7),
 (4, 5, 6, 7),
 (0, 1, 2, 3, 4),
 (0, 1, 2, 3, 5),
 (0, 1, 2, 3, 6),
 (0, 1, 2, 3, 7),
 (0, 1, 2, 4, 5),
 (0, 1, 2, 4, 6),
 (0, 1, 2, 4, 7),
 (0, 1, 2, 5, 6),
 (0, 1, 2, 5, 7),
 (0, 1, 2, 6, 7),
 (0, 1, 3, 4, 5),
 (0, 1, 3, 4, 6),
 (0, 1, 3, 4, 7),
 (0, 1, 3, 5, 6),
 (0, 1, 3, 5, 7),
 (0, 1, 3, 6, 7),
 (0, 1, 4, 5, 6),
 (0, 1, 4, 5, 7),
 (0, 1, 4, 6, 7),
 (0, 1, 5, 6, 7),
 (0, 2, 3, 4, 5),
 (0, 2, 3, 4, 6),
 (0, 2, 3, 4, 7),
 (0, 2, 3, 5, 6),
 (0, 2, 3, 5, 7),
 (0, 2, 3, 6, 7),
 (0, 2, 4, 5, 6),
 (0, 2, 4, 5, 7),
 (0, 2, 4, 6, 7),
 (0, 2, 5, 6, 7),
 (0, 3, 4, 5, 6),
 (0, 3, 4, 5, 7),
 (0, 3, 4, 6, 7),
 (0, 3, 5, 6, 7),
 (0, 4, 5, 6, 7),
 (1, 2, 3, 4, 5),
 (1, 2, 3, 4, 6),
 (1, 2, 3, 4, 7),
 (1, 2, 3, 5, 6),
 (1, 2, 3, 5, 7),
 (1, 2, 3, 6, 7),
 (1, 2, 4, 5, 6),
 (1, 2, 4, 5, 7),
 (1, 2, 4, 6, 7),
 (1, 2, 5, 6, 7),
 (1, 3, 4, 5, 6),
 (1, 3, 4, 5, 7),
 (1, 3, 4, 6, 7),
 (1, 3, 5, 6, 7),
 (1, 4, 5, 6, 7),
 (2, 3, 4, 5, 6),
 (2, 3, 4, 5, 7),
 (2, 3, 4, 6, 7),
 (2, 3, 5, 6, 7),
 (2, 4, 5, 6, 7),
 (3, 4, 5, 6, 7),
 (0, 1, 2, 3, 4, 5),
 (0, 1, 2, 3, 4, 6),
 (0, 1, 2, 3, 4, 7),
 (0, 1, 2, 3, 5, 6),
 (0, 1, 2, 3, 5, 7),
 (0, 1, 2, 3, 6, 7),
 (0, 1, 2, 4, 5, 6),
 (0, 1, 2, 4, 5, 7),
 (0, 1, 2, 4, 6, 7),
 (0, 1, 2, 5, 6, 7),
 (0, 1, 3, 4, 5, 6),
 (0, 1, 3, 4, 5, 7),
 (0, 1, 3, 4, 6, 7),
 (0, 1, 3, 5, 6, 7),
 (0, 1, 4, 5, 6, 7),
 (0, 2, 3, 4, 5, 6),
 (0, 2, 3, 4, 5, 7),
 (0, 2, 3, 4, 6, 7),
 (0, 2, 3, 5, 6, 7),
 (0, 2, 4, 5, 6, 7),
 (0, 3, 4, 5, 6, 7),
 (1, 2, 3, 4, 5, 6),
 (1, 2, 3, 4, 5, 7),
 (1, 2, 3, 4, 6, 7),
 (1, 2, 3, 5, 6, 7),
 (1, 2, 4, 5, 6, 7),
 (1, 3, 4, 5, 6, 7),
 (2, 3, 4, 5, 6, 7),
 (0, 1, 2, 3, 4, 5, 6),
 (0, 1, 2, 3, 4, 5, 7),
 (0, 1, 2, 3, 4, 6, 7),
 (0, 1, 2, 3, 5, 6, 7),
 (0, 1, 2, 4, 5, 6, 7),
 (0, 1, 3, 4, 5, 6, 7),
 (0, 2, 3, 4, 5, 6, 7),
 (1, 2, 3, 4, 5, 6, 7),
 (0, 1, 2, 3, 4, 5, 6, 7)]

---

与不同的

r

长度一起使用（例如

范围（2，列数+1）

不清楚您想要做什么，但这听起来很像

itertools.compositions

的工作。谢谢，我想把我提到的方括号内的数字打印出来。@Alambek logic，如果您有[1,2]。。。。[17]为什么没有[1,2,3]…[1,2,7]数据帧的索引

df.iloc[：，[0,1,2,3]

必须使用intertools

df.iloc[：，[i，j，k，…]生成的i，j，k来访问。

使用不同的

r

长度（例如

范围（2，列数+1）

itertools.compositions你想做什么还不太清楚，但这听起来很像是itertools.compositions的工作。谢谢你，我想把我提到的方括号内的数字打印出来。@Alambek logic，如果你有[1,2]…[17]为什么没有[1,2,3]…[1,2,7]数据框的索引

df.iloc[：，[0，1，2，3]

必须使用intertools

df.iloc[：，[i，j，k，…]]生成的i，j，k…访问；

感谢您的回复；我正在使用以下代码：

从itertools导入组合编号=[]A=[0,1,2,3,4,5,6,7]对于范围（8）中的i:for combo in compositions（A，i+2）：numbers.append（combo）

但是现在我无法运行用iloc命令生成的数字。就像这样：

df.iloc[：，[I，j，k，…]]

@Alambek

i+2

运行到

9

，但您的序列只有8个元素。而且

it.combinations

返回元组，因此您需要转换为

list

，以便与

iloc

一起使用。感谢您的回复；我正在使用以下代码：

来自itertools的导入组合编号=[]A=[0,1,2,3,4,5,6,7]对于范围内的i（8）：对于组合中的combo（A，i+2）：numbers.append（combo）

但是现在我无法运行用iloc命令生成的数字。这样：

df.iloc[：，[i，j，k，…]

@Alambek

i+2

一直运行到

9

，但您的序列只有8个元素。而且

it.combines

返回元组，因此您需要转换为

list

，以便与

iloc

一起使用。