用python写一个杨辉三角

下面是一个使用Python语言编写杨辉三角的示例代码：

# 定义函数，num为行数
def pascal_triangle(num):
    # 创建一个二维数组，用于存储杨辉三角
    triangle = [[1] * (i + 1) for i in range(num)]
    for i in range(num):
        for j in range(1, i):
            triangle[i][j] = triangle[i - 1][j - 1] + triangle[i - 1][j]
    return triangle

# 测试代码
if __name__ == '__main__':
    triangle = pascal_triangle(10)
    for row in triangle:
        print(row)

输出结果：

[1]
[1, 1]
[1, 2, 1]
[1, 3, 3, 1]
[1, 4, 6, 4, 1]
[1, 5, 10, 10, 5, 1]
[1, 6, 15, 20, 15, 6, 1]
[1, 7, 21, 35, 35, 21, 7, 1]
[1, 8, 28, 56, 70, 56, 28, 8, 1]
[1, 9, 36, 84, 126, 126, 84, 36, 9, 1]