subset sum dynamic programming

    def isSubsetSum (self, n, arr, sum):
        # code here
        sos=[[False]*(sum+1) for i in range(n+1)]
        for i in range(sum+1):
            sos[0][i]=False
        for i in range(n+1):
            sos[i][0]=True
        for i in range(1,n+1):
            for j in range(1,sum+1):
                if arr[i-1]>j:
                    sos[i][j]=sos[i-1][j]
                else:
                    sos[i][j]=sos[i-1][j] or sos[i-1][j-arr[i-1]]
        return sos[-1][-1]