打印空心等边三角形:
#!/usr/bin/python
# -*- coding: UTF-8 -*-
# 打印空心等边三角形
rows =int(raw_input('输入行数：'))
for i in range(0, rows):
for k in range(0,2* rows -1):
if(i != rows -1)and(k == rows - i -1or k == rows + i -1):
print" * ",
elif i == rows -1:
if k %2==0:
print" * ",
else:
print" ",
else:
print" ",
print"\n"
