What is this syntax?

[hshivaraj]

Hi all,

Can anyone please explain me whats going on here? Ive never seen this syntax before.

    def judgeCircle(cls, moves):

       def moves_xy(moves):
            return {
                'R': [1, 0],
                'L': [-1, 0],
                'U': [0, 1],
                'D': [0, -1]
            }[moves]

        x = 0
        y = 0

        for move_temp in moves:
            coor = moves_xy(move_temp)
            x = x + coor[0]
            y = y + c[icode]oor[1]

Im really puzzled with the syntax moves_xy. Can anyone explain me understand this new format?

[micseydel]

It's a dictionary defined and then a value is immediately pulled from it. The dictionary could be moved out into a global constant, and then "moves" fetched from it and it would be semantically the same.

[hshivaraj]

Ofcourse. Apparently this approach is much faster compared to others. In fact very fast. Not sure how.

[micseydel]

It uses a hash, so that helps. The if/elif/elif/elif alternative has to check the first three values anytime it turns out it needs the fourth.