python小技巧之把list组合成chain

a=[]                                                                    

for i in range(10): 
   a.append(i) 
                                                                        


for i,j in zip(a[:-1],a[1:]): 
    print('%s=>%s'%(i,j)) 
输出结果:

0=>1

1=>2

2=>3

3=>4

4=>5

5=>6

6=>7

7=>8

8=>9