파이썬 예제 : 달팽이 그리기, 똬리배열

import random
 
def printArray(ary):
    for i in ary:
        for j in i:
            print('%3d' % j, end=' ')
        print()
 
def snailArray(ary):
 
    offset=0
    num=1
    nrows=5
    ncols=5
 
    while nrows>0 and ncols>0:
 
        for i in range(offset,offset+ncols):
            ary[offset][i]=num
            num+=1
 
        for i in range(offset+1,offset+nrows):
            ary[i][offset+ncols-1]=num
            num+=1
 
        for i in range(offset+ncols-2,offset-1,-1):
            ary[offset+nrows-1][i]=num
            num+=1
 
        for i in range(offset+nrows-2, offset, -1):
            ary[i][offset]=num
            num+=1
 
        offset+=1
        nrows-=2
        ncols-=2
 
 
ary = [[0,0,0,0,0], [0,0,0,0,0], [0,0,0,0,0], [0,0,0,0,0], [0,0,0,0,0]]
 
snailArray(ary)
printArray(ary)

5행 5열짜리 달팽이 그리기 예제이다. 똬리배열이라고도 부른다.