python如何格式化输出杨辉三角

在Python中，可以使用嵌套循环和字符串格式化功能来输出杨辉三角。以下是一个示例代码：

def generate_pascals_triangle(n):
    triangle = []
    for i in range(n):
        row = [1]
        if triangle:
            last_row = triangle[-1]
            row.extend([sum(pair) for pair in zip(last_row, last_row[1:])])
            row.append(1)
        triangle.append(row)
    return triangle

def print_pascals_triangle(triangle):
    n = len(triangle)
    max_width = 2 * n - 1
    for i, row in enumerate(triangle):
        row_str = " ".join(str(num) for num in row)
        padding = (max_width - len(row_str)) // 2
        print(" " * padding + row_str + " " * padding)

n = int(input("请输入杨辉三角的行数："))
triangle = generate_pascals_triangle(n)
print_pascals_triangle(triangle)

这段代码首先定义了两个函数：generate_pascals_triangle()用于生成杨辉三角，print_pascals_triangle()用于打印杨辉三角。然后，根据用户输入的行数生成杨辉三角并打印出来。