1 user = {
 2     'xiaoming':'123',
 3     'xiaobai':'111',
 4     'xiaowang':'222'
 5 }
 6 # 直接循环字典，每次取到值的值是key
 7 for i in user:
 8    print("%s ==> %s" % (i,user.get(i)))
 9 
10 for k,v in user.items():
11     print("%s ==> %s" % (k,v))