solution.py

# You live in the city of Cartesia where all roads are laid out in a perfect grid.
# You arrived ten minutes too early to an appointment, so you decided to take the opportunity to go for a short walk.
# The city provides its citizens with a Walk Generating App on their phones --
# everytime you press the button it sends you an array of one-letter strings representing directions to walk
# (eg. ['n', 's', 'w', 'e']).
# You always walk only a single block in a direction and you know it takes you one minute to traverse one city block,
# so create a function that will return true if the walk the app gives you will take you exactly ten minutes
# (you don't want to be early or late!) and will, of course, return you to your starting point. Return false otherwise.

# Note: you will always receive a valid array containing a random assortment of
# direction letters ('n', 's', 'e', or 'w' only).
# It will never give you an empty array (that's not a walk, that's standing still!).


def isValidWalk(walk):
    if len(walk) == 10:
        north_south, west_east = 0, 0

        for i in walk:
            if i == 'n':
                north_south += 1
            if i == 's':
                north_south -= 1

            if i == 'w':
                west_east += 1

            if i == 'e':
                west_east -= 1

        return not north_south and not west_east

    return False