Python multiple loops

Question

A = [[[1,2,3],[4]],[[1,4],[2,3]]]

Here I want to find lists in A which sum of all sublists in list not grater than 5.

Which the result should be [[1,4],[2,3]]

I tried a long time to solve this problem in python. But I still can't figure out the right solution, which I stuck at loop out multiple loops. My code as follows, but its obviously wrong, how to correct it?

A = [[[1,2,3],[4]],[[1,4],[2,3]]]
z = []
for l in A:
    for list in l:
        sum = 0
        while sum < 5:
            for i in list:
                sum+=i
        else:
            break
    else:
        z.append(l)
print z

Asking for help~

Your more likely to get help if you post some code, preferably a minimal reproducible example. That shows us that you've tried to solve this problem yourself, and we can point out why your code doesn't do what you want it to do. — PM 2Ring
– PM 2Ring, Commented Apr 26, 2017 at 9:34
First of all the premise of this question is not very clear. What kind of input do you expect? Are the lists nested to only 3 levels? — Cong Ma
– Cong Ma, Commented Apr 26, 2017 at 9:35

Kruupös · Accepted Answer · 2017-04-26 09:48:21Z

2

Simplification of @KindStranger method in a one-liner:

>> [sub for x in A for sub in x if max(sum(sub) for sub in x) <= 5]
[[1, 4], [2, 3]]

answered Apr 26, 2017 at 9:48

Kruupös

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Comments

Gaurav Ojha · Accepted Answer · 2017-04-26 09:38:31Z

0

A simple solution which you can think of would be like this -

A = [[[1,2,3],[4]],[[1,4],[2,3]]]

r = []   # this will be our result

for list in A:  # Iterate through each item in A
    f = True    # This is a flag we set for a favorable sublist
    for item in list:  # Here we iterate through each list in the sublist
        if sum(item) > 5:  # If the sum is greater than 5 in any of them, set flag to false
            f = False
    if f:       # If the flag is set, it means this is a favorable sublist
        r.append(list)

print r

But I'm assuming the nesting level would be the same. http://ideone.com/hhr9uq

answered Apr 26, 2017 at 9:38

Gaurav Ojha

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3 Comments

Stellera Over a year ago

Thanks. This is exactly what I am looking for.

Kruupös Over a year ago

@GauravOjha, Instead of the boolean f you can use a Else Clauses on Loop Statements to do exactly the same thing. Please have a look at the link.

Stellera Over a year ago

Thanks for noticing.

Kind Stranger · Accepted Answer · 2017-04-26 09:36:42Z

0

This should work for your problem:

>>> for alist in A:
...     if max(sum(sublist) for sublist in alist) <= 5:
...         print(alist)
...
[[1, 4], [2, 3]]

answered Apr 26, 2017 at 9:36

Kind Stranger

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Comments

JkShaw · Accepted Answer · 2017-04-26 10:10:27Z

0

The one with all()

[t for item in A for t in item if all(sum(t)<=5 for t in item)]

answered Apr 26, 2017 at 10:10

JkShaw

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