Wsrtjtyk

from typing import List

def find_peak(m: List[List[int]]) -> List[int]:

    """

    Given an non-empty elevation map m, returns the cell of the

    highest point in m.



Examples (note some spacing has been added for human readablity)

>>> m = [[1,2,3],

         [9,8,7],

         [5,4,6]]

>>> find_peak(m)

[1,0]

>>> m = [[6,2,3],

         [1,8,7],

         [5,4,9]]

>>> find_peak(m)

[2,2]

"""

max_location = 

for sublist in m:

    max_location.append(max(sublist))

max_location = max(max_location)

for sublist in m:

    if max_location in sublist:

        return (m.index(max_location),sublist.index(max_location))

this doesnt really work since it just returns that number is not in list

You can also make good use of enumerate. First find the row (with its index) with the maximum number. Then find that number and its index in that row.

In both cases you need to provide a key to the max function so that it considers the value (not the index):

def find_peak(m):

    i, max_row = max(enumerate(m), key=lambda x: max(x[1]))

    j, max_val = max(enumerate(max_row), key=lambda x: x[1])

    return [i, j]

Output

print(find_peak([[1,2,3], [9,8,7], [5,4,6]]))

# [1, 0]

print(find_peak([[6,2,3], [1,8,7], [5,4,9]]))

# [2, 2]

You can find the maximum value in the flattened input structure, and then return the coordinates that specify the location of the maximum value previously found:

from typing import List

def find_peak(m: List[List[int]]) -> List[int]:

  _max = max([i for b in m for i in b])

  return [[i, a] for i in range(len(m)) for a in range(len(m[0])) if m[i][a] == _max][0]



print(list(map(find_peak, [[[1, 2, 3], [9, 8, 7], [5, 4, 6]], [[6, 2, 3], [1, 8, 7], [5, 4, 9]]])))

Output:

[[1, 0], [2, 2]]

I think its easier when you think about iterating over indices rather than the items on the list:

from itertools import product



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



# generate all indices

x_len = range(len(d))

y_len = range(len(d[0]))

indices = product(x_len, y_len)



# select maximal item by index

key = lambda x: d[x[0]][x[1]]

max_index = max(indices, key=key)



print(max_index)