Python: specific value in a named tuple of a list of tuples

Question

I was wondering if it is possible to print a value that is inside a list of lists of tuples if you already know the indexes path.

1. List[i][j]
2.   list2[x][y]
3.      list3[z][w]
4.         etc.

I would like to do something like this:

str( list[i][0 [0][2 [0][0]] )

To get the value at indexes 0,0 in the tuple at indexes 0,2 of a list at indexes i,0 of the main list.

Edit: Sorry, I'm learning. Console returns this:

    [Record(items=set({'item1','item2'}),
            id=6439,
            stats=[OrderedStatistic(items_b=set({'item2'}),
                                    items_a=set({'item1'}),
                                    row=123,
                                    col=321)]),
     Record(...

I'm looking for the "row" value. I didn't know it had a name, it wasn't showed in my viewer.

Edit 2:

Improvement. It works, but I'm using a temporary variable because oldList[0].stats[0].row returns a 'stats' object has no attribute row.

for i in range(0, len(oldList)):
    tmpList = oldList[i][2]
    newList.append('ID:\t' + str(oldList[i][1])+ '\nROW:\t' + str(tmpList[0][2])

or

for i in range(0, len(oldList)):
    tmpList = oldList[i][2]
    newList.append('ID:\t' + str(oldList[i][1])+ '\nROW:\t' + str(tmpList[0].row)

If indexing the object results in a sequence, just index that as well. — Ignacio Vazquez-Abrams, May 07 '18 at 15:51
Short answer is yes. Could you provide sample data (even fake), which is correctly structured? — Mika72, May 07 '18 at 15:52
@dawg Sorry, I don't know what you mean with input tuple or desired output. — Falk, May 07 '18 at 16:54
Are those [named tuples](https://docs.python.org/2/library/collections.html#collections.namedtuple) you have there? — dawg, May 07 '18 at 17:11
Yes! I didn't know they had names, my Spyder viewer uses index as names and I assumed they were nameless. — Falk, May 07 '18 at 17:25

score 0 · Answer 1 · answered May 07 '18 at 16:17

0

The syntax in this case would be as follows:

print(lst[i][0][0][2][0][0])

That nested structure is more than just a list of lists of tuples though. If that were the case, then the following minimal example list could have the 'a' referenced with a simple lst[0][0][0]:

lst = [[('a', 'b', 'c'), ('d', 'e', 'f')]]

answered May 07 '18 at 16:17

Brandon Krueger

156
5

Thank you Brandon. `lst = [[('a', 'b', 'c'), ('d', ('e1' , 'e2'), 'f')]]` It should look like this, with e2 as the value I'm looking for. I also updated my original post with a sample. – Falk May 07 '18 at 17:11
In that case, you would want `lst[0][1][1][1]`. – Brandon Krueger May 07 '18 at 17:28
Yes, I already tried but it returns a `TypeError "set" object does not support indexing` That was my first attempt. I made a test on an array and it works. I'm probably misreading the lists. – Falk May 07 '18 at 17:40
For your example, try `lst[0].stats[0].row`. – Brandon Krueger May 07 '18 at 17:52
It doesn't work, but you helped me a lot! I edited my post to make it a bit more readable. – Falk May 07 '18 at 19:33

Mehrdad Pedramfar · Answer 2 · 2018-05-08T11:17:19.300

In a simple way for the lst = [[('a', 'b', 'c'), ('d', ('e1' , 'e2'), 'f')]] example you can use lst[0][1][1][1] to reach e2, but I imagine that you have the indexes in an array like ind_array. in this case you may have to do something like this:

ind_array = [0, 1, 1, 1]
desired_value = lst
for i in o :
    try:
        desired_value = desired_value[i]
     except IndexError:
         print('index not found.')
         break
 print(desired_value)

Let me know if you have problem with answer or you will have the indexes differently.

Python: specific value in a named tuple of a list of tuples

2 Answers2