IndexError: list index out of range using nested for loops

Question

I'm programming in CoCalc (Sage which is Python 2.7 with some extras added) for doing very simple stuff and I am having trouble. I must admit I am not a frequent programmer so probably I am missing something which should be fairly obvious.

to put the question in context. max_faces_list is a list of sets. I want to remove from the list the elements which are subsets of other elements.

The code is:

for i in range(0,len(max_faces_list)-2):
i
for j in range(i+1,len(max_faces_list)):
    j
    if max_faces_list[i].issubset(max_faces_list[j]):
        print('bu')
        F.remove(F[i])
        break

The output is:

0
1
2
3
4
bu
1
2
3
4
bu
2
3
4
5
bu
3
4
5
6
bu
4
5
6
7
8
9
10
bu
5
6
7
8
9
10
bu
6
7
8
9
10
11
bu
7
8
9
10
bu
Error in lines 1-8
Traceback (most recent call last):
  File "/cocalc/lib/python2.7/site-packages/smc_sagews/sage_server.py", line 1013, in execute
    exec compile(block+'\n', '', 'single') in namespace, locals
  File "", line 7, in <module>
IndexError: list index out of range

In case it is helpful:

max_faces_list=[set([(0, 2, 3)]), set([(0, 1, 2)]), set([(1, 2, 3)]), set([(0, 1, 3)]), set([(0, 2, 3), (0, 1, 2)]), set([(0, 2, 3), (1, 2, 3)]), set([(0, 2, 3), (0, 1, 3)]), set([(0, 1, 2), (1, 2, 3)]), set([(0, 1, 2), (0, 1, 3)]), set([(1, 2, 3), (0, 1, 3)]), set([(0, 2, 3), (0, 1, 2), (1, 2, 3)]), set([(0, 2, 3), (0, 1, 2), (0, 1, 3)]), set([(0, 2, 3), (1, 2, 3), (0, 1, 3)]), set([(0, 1, 2), (1, 2, 3), (0, 1, 3)])]

F=[Simplicial complex with vertex set (0, 2, 3) and facets {(0, 2, 3)}, Simplicial complex with vertex set (0, 1, 2) and facets {(0, 1, 2)}, Simplicial complex with vertex set (1, 2, 3) and facets {(1, 2, 3)}, Simplicial complex with vertex set (0, 1, 3) and facets {(0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (0, 1, 2)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (1, 2, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 1, 2), (1, 2, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 1, 2), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(1, 2, 3), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (0, 1, 2), (1, 2, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (0, 1, 2), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (1, 2, 3), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 1, 2), (1, 2, 3), (0, 1, 3)}]

I have introduced some code (i, j and print('bu') in order to try to detect and understand what is going on.

EDIT:

With the code:

for i in range(0,len(max_faces_list)-2):
    i
    for j in range(i+1,len(max_faces_list)):
        j
        if max_faces_list[i].issubset(max_faces_list[j]):
            print('bu')
            print(i, F)
            F.remove(F[i])
            break

The output is:

0
1
2
3
4
bu
(0, [Simplicial complex with vertex set (0, 2, 3) and facets {(0, 2, 3)}, Simplicial complex with vertex set (0, 1, 2) and facets {(0, 1, 2)}, Simplicial complex with vertex set (1, 2, 3) and facets {(1, 2, 3)}, Simplicial complex with vertex set (0, 1, 3) and facets {(0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (0, 1, 2)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (1, 2, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 1, 2), (1, 2, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 1, 2), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(1, 2, 3), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (0, 1, 2), (1, 2, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (0, 1, 2), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (1, 2, 3), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 1, 2), (1, 2, 3), (0, 1, 3)}])
1
2
3
4
bu
(1, [Simplicial complex with vertex set (0, 1, 2) and facets {(0, 1, 2)}, Simplicial complex with vertex set (1, 2, 3) and facets {(1, 2, 3)}, Simplicial complex with vertex set (0, 1, 3) and facets {(0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (0, 1, 2)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (1, 2, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 1, 2), (1, 2, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 1, 2), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(1, 2, 3), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (0, 1, 2), (1, 2, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (0, 1, 2), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (1, 2, 3), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 1, 2), (1, 2, 3), (0, 1, 3)}])
2
3
4
5
bu
(2, [Simplicial complex with vertex set (0, 1, 2) and facets {(0, 1, 2)}, Simplicial complex with vertex set (0, 1, 3) and facets {(0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (0, 1, 2)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (1, 2, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 1, 2), (1, 2, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 1, 2), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(1, 2, 3), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (0, 1, 2), (1, 2, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (0, 1, 2), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (1, 2, 3), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 1, 2), (1, 2, 3), (0, 1, 3)}])
3
4
5
6
bu
(3, [Simplicial complex with vertex set (0, 1, 2) and facets {(0, 1, 2)}, Simplicial complex with vertex set (0, 1, 3) and facets {(0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (1, 2, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 1, 2), (1, 2, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 1, 2), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(1, 2, 3), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (0, 1, 2), (1, 2, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (0, 1, 2), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (1, 2, 3), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 1, 2), (1, 2, 3), (0, 1, 3)}])
4
5
6
7
8
9
10
bu
(4, [Simplicial complex with vertex set (0, 1, 2) and facets {(0, 1, 2)}, Simplicial complex with vertex set (0, 1, 3) and facets {(0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (1, 2, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 1, 2), (1, 2, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 1, 2), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(1, 2, 3), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (0, 1, 2), (1, 2, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (0, 1, 2), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (1, 2, 3), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 1, 2), (1, 2, 3), (0, 1, 3)}])
5
6
7
8
9
10
bu
(5, [Simplicial complex with vertex set (0, 1, 2) and facets {(0, 1, 2)}, Simplicial complex with vertex set (0, 1, 3) and facets {(0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (1, 2, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 1, 2), (1, 2, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(1, 2, 3), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (0, 1, 2), (1, 2, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (0, 1, 2), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (1, 2, 3), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 1, 2), (1, 2, 3), (0, 1, 3)}])
6
7
8
9
10
11
bu
(6, [Simplicial complex with vertex set (0, 1, 2) and facets {(0, 1, 2)}, Simplicial complex with vertex set (0, 1, 3) and facets {(0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (1, 2, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 1, 2), (1, 2, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(1, 2, 3), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (0, 1, 2), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (1, 2, 3), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 1, 2), (1, 2, 3), (0, 1, 3)}])
7
8
9
10
bu
(7, [Simplicial complex with vertex set (0, 1, 2) and facets {(0, 1, 2)}, Simplicial complex with vertex set (0, 1, 3) and facets {(0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (1, 2, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 1, 2), (1, 2, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(1, 2, 3), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 2, 3), (0, 1, 2), (0, 1, 3)}, Simplicial complex with vertex set (0, 1, 2, 3) and facets {(0, 1, 2), (1, 2, 3), (0, 1, 3)}])
Error in lines 2-10
Traceback (most recent call last):
  File "/cocalc/lib/python2.7/site-packages/smc_sagews/sage_server.py", line 1013, in execute
    exec compile(block+'\n', '', 'single') in namespace, locals
  File "", line 8, in <module>
IndexError: list index out of range

So the error is that I no longer can remove F[i]. Thanks @Akash Wankhede for spotting this!! I think I have understood my mistake!

Can you please add this statement "print(i, F)"just below "print('bu')", and share the output? — Akash Wankhede, Dec 27 '17 at 12:17
@AkashWankhede , if you write your previous comment as an answer I will accept it :) — D1811994, Dec 27 '17 at 13:28
I have posted it as answer. I am glad that it helps you. You can upvote my answer. — Akash Wankhede, Dec 27 '17 at 13:32

score 1 · Accepted Answer · answered Dec 27 '17 at 13:31

1

Please add this statement "print(i, F)"just below "print('bu')", you might find whats wrong going on.

answered Dec 27 '17 at 13:31

Akash Wankhede

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IndexError: list index out of range using nested for loops

1 Answers1