Count each unique element in list of lists

[Yaşar Arabacı]

Hi,

I have a function that returns something like this;

[[[1, 5, 9], [2, 6, 7], [3, 4, 8]], [[1, 6, 8], [2, 4, 9], [3, 5, 7]]]

It is a list of list of lists. Each uppermost list is called a result.
I want to write a code that
shows that each elem in sublists of result on appears once in whole
sublist in order to add it to
my doctest. I am looking for something like this;

for result in results:
print sum(1 for group in result for item in group)

[1, 1, 1, 1, 1, 1, 1, 1, 1]
[1, 1, 1, 1, 1, 1, 1, 1, 1]

Above code gives me 9,9. but I want the example output above.

I prefer a one liner because this is supposed to go into a doctest.
--
http://ysar.net/

[yasar...@gmail.com]

This works;

>>> for result in results:
flat = list(item for group in result for item in group)
print [sum([1 for el in flat if el==current]) for current in flat]

[1, 1, 1, 1, 1, 1, 1, 1, 1]
[1, 1, 1, 1, 1, 1, 1, 1, 1]

But I am still open to suggestions if anyone thinks this can be improved.

[Chris Angelico]

On Sat, Nov 9, 2013 at 6:28 AM, Yaşar Arabacı <yasar...@gmail.com> wrote:
> I want to write a code that
> shows that each elem in sublists of result on appears once in whole
> sublist in order to add it to
> my doctest.

So, to clarify the problem: You want to ensure that every element
occurs exactly once, neither more nor less? And you have a guarantee
that the lists and sublists have a specific nesting depth? Try this:

[sorted((x for l in result for x in l)) for result in results]

Flattens and sorts the lists.

[sorted((x for l in result for x in l))==list(range(1,10)) for result
in results]

Flattens, sorts, and compares with a template list (which in this case
is [1, 2, 3, 4, 5, 6, 7, 8, 9] from range()).

ChrisA

[Vlastimil Brom]

2013/11/8 Yaşar Arabacı <yasar...@gmail.com>:

> Hi,
>
> I have a function that returns something like this;
>
> [[[1, 5, 9], [2, 6, 7], [3, 4, 8]], [[1, 6, 8], [2, 4, 9], [3, 5, 7]]]
>
> It is a list of list of lists. Each uppermost list is called a result.

> I want to write a code that
> shows that each elem in sublists of result on appears once in whole
> sublist in order to add it to

> my doctest. I am looking for something like this;
>
> for result in results:

> print sum(1 for group in result for item in group)

>
> [1, 1, 1, 1, 1, 1, 1, 1, 1]
> [1, 1, 1, 1, 1, 1, 1, 1, 1]
>

> Above code gives me 9,9. but I want the example output above.
>
> I prefer a one liner because this is supposed to go into a doctest.
> --
> http://ysar.net/

> --
> https://mail.python.org/mailman/listinfo/python-list


Hi,
depending on the specification, the tests could be e.g.:
results = [[[1, 5, 11], [2, 6, 7], [3, 4, 8]], [[1, 6, 8], [2, 4, 9],
[3, 5, 7]]]

#testing for the sum 1..9 - this would also pass for some "paired"
repeated items, which most likely isn't indended
print all(sum((elem for sublist in result for elem in sublist))==45
for result in results)

# testing for different items without repeating - not only 1..9
print all(len(set(elem for sublist in result for elem in sublist))==9
for result in results)

# testing explicitely for items 0..9 in any order
print all((set(elem for sublist in result for elem in
sublist))==set([1,2,3,4,5,6,7,8,9]) for result in results)

hth,
vbr