python之字典dict的for循環

以下方法等同，都可以獲取key和value
1.#獲取KEY和value
dir_test={ 'n':"psu",'v':"電壓",'c':"電流"}
for key,value in dir_test.items():
   print(key,value)
2#獲取KEY和value

for i,j in dir_test.items():
   #print("key:%s"%i,"value:%s"%dir_test[i])
   print("key:%s"%i,"value:%s"%j)

#獲取value
for value in dir_test.values():
      print(value)
#獲取key

for key in dir_test.keys():
   print(key)