How to select a serie of sublists according to an other list

Cyrille
1409 ●38 ●82 ●144

One more time this is certainly the result of my lack of expertise in programming but I encounter the following problem.

I have a list of lists

A=[[3, 2, 1, 1, 0, 0, 0, 5],   [4, 3, -1, 0, -1, 1, 0, 4],   [1, 2, 2, 0, 0, 0, 1, 2]]

and an other list

B=[3,5]

What I want is to select a sublist of the list A according to the following criterion : keep the sublist A[i] if A[i][j]==1 for j in B

Comments

This is a bit ambiguous, as revealed by the proposed answer: do you mean "for all j in B" or "for some j in B"?

John Palmieri ( 3 years ago )

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6932 ●9 ●52 ●162

It's quite straightforward:

[a for a in A if all(a[j]==1 for j in B)]

On my computer the effect of your proposal is an empty list when it should be [[3, 2, 1, 1, 0, 0, 0, 5], [4, 3, -1, 0, -1, 1, 0, 4]]

Cyrille ( 3 years ago )

It seems that you search for the sublists of A containing an element of B. If it is effectively the case, then try

sage: [a for a in A if any(aj in B for aj in a)]
[[3, 2, 1, 1, 0, 0, 0, 5], [4, 3, -1, 0, -1, 1, 0, 4]]

David Coudert ( 3 years ago )

My answer solves the problem you posed. If the answer is different from expected, then you posed the problem incorrectly.

Max Alekseyev ( 3 years ago )

Please start posting anonymously - your entry will be published after you log in or create a new account.

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Asked: 3 years ago

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Last updated: Mar 03 '22