#coding:utf-8
import os

os.system('clear')
x = int(input('the number of lines:'))
for i in range(0,x):
	for j in range(0, x-i):
		print(' ', end='')
	for j in range(0, i*2-1):
		print('*', end='')
	print('\n')
for i in range(x,0,-1):
	for j in range(x-i,0,-1):
		print(' ', end='')
	for j in range(i*2-1,0,-1):
		print('*', end='')
	print('\n')
        

実行結果