Printing list of list (containing integers) in lexicographic order

Question

Task:You are given three integers x,y and z along with an integer n. You have to print a list of all possible coordinates where the sum of is not equal to n. Print Print the list in lexicographic increasing order. Below is my code. Works fine except for printing in lexicographic order. Below is my code.Is there a better approach to get lexicographic order of list containing integers?

from itertools import combinations
lst=[]
if __name__ == '__main__':
    x = int(input())
    y = int(input())
    z = int(input())
    n = int(input())
    lst=[[a,b,c]  for b in range(y+1) for c in range(z+1)   for a in range(x+1) ]

finallst=[]
for items in combinations(lst,3):
    for nums in items:
       x=sum(nums)
       if x!=n and nums not in finallst:
            finallst.append(nums)

f_finallst= (sorted(map(str,(finallst)))) #converted to string to get lexicographic order
print (f_finallst) 
My result=['[0, 0, 0]', '[0, 0, 1]', '[0, 1, 0]', '[1, 0, 0]', '[1, 1, 1]']
Expected result=[[0, 0, 0], [0, 0, 1], [0, 1, 0], [1, 0, 0], [1, 1, 1]]

Just do `finallst.sort()` without converting the lists to strings. — Aran-Fey, Aug 30 '18 at 17:46
When you say lexicographical order, you mean character by character or element by element? By example, which of these is ordered: [[100, 0], [90, 0]] or [[90, 0], [100, 0]] — Olivier Melançon, Aug 30 '18 at 17:50

score 1 · Answer 1 · edited Dec 20 '19 at 04:57

1

x = int(input())
y = int(input())
z = int(input())
n = int(input())
lists=[[i,j,k] for i in range(x+1)
               for j in range(y+1)
               for k in range(z+1) if (i+j+k)!=n]
print(lists)

edited Dec 20 '19 at 04:57

Dmitry Kuzminov

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answered Dec 20 '19 at 02:56

Haris Aqeel

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Explain your answer. What is happening here? – Aksen P Dec 20 '19 at 08:25

score 0 · Accepted Answer · answered Aug 30 '18 at 17:45

0

print([coords 
       for coords in itertools.product(range(x+1), range(y+1), range(z+1))
       if sum(coords) != n])

answered Aug 30 '18 at 17:45

BallpointBen

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You may add some explanation to improve the usefulness of your answer. – Moses Koledoye Aug 30 '18 at 17:56

score 0 · Answer 3 · answered Aug 30 '18 at 17:46

0

By using map(str, finallst), you cast each of the element in the list to a str. You want to keep the elements as they are, but use str as a sorting key.

f_finallst= sorted(finallst, key=str)

answered Aug 30 '18 at 17:46

Olivier Melançon

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You don't need string at all! – Moses Koledoye Aug 30 '18 at 17:47
For lexicographical order, yes, suppose there is a two-digit number in the list, then it makes a difference – Olivier Melançon Aug 30 '18 at 17:47
Ok, Fair enough. But converting the entire list to string might have you comparing numbers with commas or spaces for cases where there are more than one digit leading to unintended results. – Moses Koledoye Aug 30 '18 at 17:51
@MosesKoledoye Although, I added a comment to ask OP to be more specific about what they mean by lexicographical order. – Olivier Melançon Aug 30 '18 at 17:52

tafadzwabmotsi · Answer 4 · 2020-11-26T02:48:44.067

I found out that adding the lambda function, which basically works as the key for the sort comparison will do the trick. For a detailed explanation read here

if __name__ == '__main__':
x = int(input())
y = int(input())
z = int(input())
n = int(input())

orginal_list = [[i, j, k] for k in range(z+1) for j in range(y+1) for i in range(x+1) if i + j + k != n]

sorted_list = sorted(orginal_list, key = lambda i: (len(i), i)) 


print(sorted_list)

Printing list of list (containing integers) in lexicographic order

4 Answers4