python dict 遍历
refer to:
https://blog.csdn.net/CuGBabyBeaR/article/details/25037687
https://blog.csdn.net/Jarry_cm/article/details/99684387
四种方式, 1, 3最快
1)
for i in d:
t = i + d[i]
2)
for k,v in d.items():
t = k + v
3)
for k,v in d.iteritems():
t = k + v
4)
for k,v in zip(d.iterkeys(),d.itervalues()):
t = k + v