CODEWITHSUNDEEP
pythonarraysnumpy
MrDuk
MrDuk

Reputation: 18242

Cleaner way to compare array values?

I have a maze:

||||||||||||||||||||||
| ||        | |    . |
|    |||||| | |||||| |
||||||        |      |
|    | |||||| || |||||
| |||| |         |   |
|        ||| |||   | |
||||||||||    |||||| |
|  P       ||        |
||||||||||||||||||||||

along with the following code:

import numpy
import copy
import collections

UP = [0,1]
DOWN = [0,-1]
LEFT = [-1,0]
RIGHT = [1,0]

theProblem = numpy.empty((rows,cols), dtype=object)

## code to generate the below matrix ##
[['|' '|' '|' '|' '|' '|' '|' '|' '|' '|' '|' '|' '|' '|' '|' '|' '|' '|'
  '|' '|' '|' '|']
 ['|' ' ' '|' '|' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' '|' ' ' '|' ' ' ' ' ' '
  ' ' ' ' ' ' '|']
 ['|' ' ' ' ' ' ' ' ' '|' '|' '|' '|' '|' '|' ' ' '|' ' ' '|' '|' '|' '|'
  '|' '|' ' ' '|']
 ['|' '|' '|' '|' '|' '|' ' ' ' ' ' ' ' ' ' ' 'P' ' ' ' ' '|' ' ' ' ' ' '
  ' ' ' ' ' ' '|']
 ['|' ' ' ' ' ' ' ' ' '|' ' ' '|' '|' '|' '|' '|' '|' ' ' '|' '|' ' ' '|'
  '|' '|' '|' '|']
 ['|' ' ' '|' '|' '|' '|' ' ' '|' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' '|'
  ' ' ' ' ' ' '|']
 ['|' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' '|' '|' '|' ' ' '|' '|' '|' ' ' ' '
  ' ' '|' ' ' '|']
 ['|' '|' '|' '|' '|' '|' '|' '|' '|' '|' ' ' ' ' ' ' ' ' '|' '|' '|' '|'
  '|' '|' ' ' '|']
 ['|' '.' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' '|' '|' ' ' ' ' ' ' ' ' ' '
  ' ' ' ' ' ' '|']
 ['|' '|' '|' '|' '|' '|' '|' '|' '|' '|' '|' '|' '|' '|' '|' '|' '|' '|'
  '|' '|' '|' '|']]
#######################################################################

# stateX = location of P[0] #
# stateY = location of P[1] #
print "WALL" if theProblem[stateX+DOWN[0],stateY+DOWN[1]] == '|' else "GO"

Is there a cleaner way to do the last line comparison? I'm pretty new to numpy, but it seems there has to be a more clever way to compare surrounding cells without explicitly doing like:

print "WALL" if theProblem[stateX+DOWN[0],stateY+DOWN[1]] == '|' else "GO"
print "WALL" if theProblem[stateX+UP[0],stateY+UP[1]] == '|' else "GO"
print "WALL" if theProblem[stateX+LEFT[0],stateY+LEFT[1]] == '|' else "GO"
print "WALL" if theProblem[stateX+RIGHT[0],stateY+RIGHT[1]] == '|' else "GO"

Upvotes: 2

Views: 85

Answers (2)

pawelswiecki
pawelswiecki

Reputation: 572

# if diagonal movements are accepted
neighbours = ((-1, -1), (0, -1), (1, -1), (-1, 0), (1, 0), (-1, 1), (0, 1), (1, 1))

# if diagonal movements are NOT accepted
neighbours = ((0, -1), (-1, 0), (1, 0), (0, 1)) 

for neighbour in neighbours:
    if theProblem[stateX + neighbour[0], stateY + neighbour[1]] == '|':
        print "WALL"
    else:
        print "GO"

Should be equivalent. This is pure Python. I don't know NumPy.

Edit: Another option (for all 8 directions):

for x in range(-1,2):
    for y in range(-1,2):
        if (x, y) != (0, 0):
            if theProblem[stateX + x, stateY + y] == '|':
                print "WALL"
            else:
                print "GO"

Upvotes: 3

jkd
jkd

Reputation: 1045

What about:

print "WALL" if ("|" in theProblem[stateX+DOWN[0],stateY+DOWN[1]] + theProblem[stateX+UP[0],stateY+UP[1]] + theProblem[stateX+RIGHT[0],stateY+RIGHT[1]] + theProblem[stateX+LEFT[0],stateY+LEFT[1]]) else "GO"

Upvotes: 0

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