Question

def compare_elevations_within_row(elevation_map: List[List[int]], map_row: int, level: int) -> List[int]:
"""Return a new list containing the three counts: the number of
elevations from row number map_row of elevation map elevation_map
that are less than, equal to, and greater than elevation level.

Precondition: elevation_map is a valid elevation map.
0 <= map_row < len(elevation_map).

>>> compare_elevations_within_row(THREE_BY_THREE, 1, 5)
[1, 1, 1]
>>> compare_elevations_within_row(FOUR_BY_FOUR, 1, 2)
[0, 1, 3]

"""
for i in elevation_map[map_row]:
differences=[0,0,0]
if i<level:
differences[0] += 1
elif i==level:
differences[1] += 1
else:
differences[2] += 1
return differences

This was written in python, I am wondering why does the header of the function shows syntax error starting from List. (List[List[int]], map_row: int, level: int) -> List[int]:)these are all underedline

Answer 1

# do comment if any problem arises

# Code

# you are missing this import

from typing import List

def compare_elevations_within_row(elevation_map: List[List[int]], map_row: int, level: int) -> List[int]:

    """Return a new list containing the three counts: the number of

    elevations from row number map_row of elevation map elevation_map

    that are less than, equal to, and greater than elevation level.

    Precondition: elevation_map is a valid elevation map.

    0 <= map_row < len(elevation_map).

    >>> compare_elevations_within_row(THREE_BY_THREE, 1, 5)

    [1, 1, 1]

    >>> compare_elevations_within_row(FOUR_BY_FOUR, 1, 2)

    [0, 1, 3]

    """

    for i in elevation_map[map_row]:

        differences = [0, 0, 0]

        if i < level:

            differences[0] += 1

        elif i == level:

            differences[1] += 1

        else:

            differences[2] += 1

    return differences

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