本质就是打印的字符和显示字符的拼接。代码如下：

def print_triangle(n):
	"""打印n行三角形"""
	for i in range(n):
		for j in range(n,i,-1):
			print(" ",end="")
		for j in range(i + 1):
			print("$",end="")
		for j in range(i):
			print("$",end="")
		print()
if __name__ == "__main__":
	print_triangle(6)