gistfile1.py

def warshall(matrix):
    n = len(matrix)
    for k in range(n):
        for i in range(n):
            for j in range(n):
                if matrix[i][k] and matrix[k][j]:
                    matrix[i][j] = 1
    return matrix
    
matrix = [[0, 0, 0, 1],
          [1, 0, 1, 0],
          [1, 0, 0, 1],
          [0, 0, 1, 0]]

transclosure = warshall(matrix)
for row in transclosure:
    print(row)
    
#[1, 0, 1, 1]
#[1, 0, 1, 1]
#[1, 0, 1, 1]
#[1, 0, 1, 1]