[root@13cml10 ~]# cat a.py 

#_*_coding:utf-8_*_


for i in range(0,12):

for a in range(0,i):

print "+",

print a,

print "=",

print sum(range(1,i))

print "\n"


[root@13cml10 ~]# python a.py 

= 0



+ 0 = 0



+ 0 + 1 = 1



+ 0 + 1 + 2 = 3



+ 0 + 1 + 2 + 3 = 6



+ 0 + 1 + 2 + 3 + 4 = 10



+ 0 + 1 + 2 + 3 + 4 + 5 = 15



+ 0 + 1 + 2 + 3 + 4 + 5 + 6 = 21



+ 0 + 1 + 2 + 3 + 4 + 5 + 6 + 7 = 28



+ 0 + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 = 36



+ 0 + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 = 45



+ 0 + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 = 55