python应用-给出行数，输出相应的杨辉三角

def main():

    num = int(input('Number of rows: '))

    yh = [[]] * num

    for row in range(num):

        yh[row] = [None] * (row + 1)

        for col in range(row+1):

            if col == 0 or col == row:

                yh[row][col] = 1

            else:

                yh[row][col] = yh[row - 1][col] + yh[row - 1][col - 1]

            print(yh[row][col], end='\t')

        print()

if __name__ == '__main__':

    main()

结果：

Number of rows: 5

1

1   1

1   2   1

1   3   3   1

1   4   6   4   1