先來一段代碼~
>>>params = {"key1":"value1", "key2":value2", "key3":"value3"}
>>>params.keys()
["key1","key2","key3"]
>>>params.values()
["value1","value2","value3"]
>>>params.items()
[("key1","value1"),("key2","value2"),("key3","value3")]
note 1. keys()返回一個包含dictionary所有key的list,
這個list也有可能不是定義dictionary時的順序, 還記得嗎?dictionary是無序的.
note 2. values()返回一個包含dictionary所有value的list,
這個list的順序跟keys()返回的list順序是一一對應的,
即對於所有i, params.values()[i] == params[ params.keys()[i] ]
note 3. items()返回一個形如(key,value)組成tuple的list, 這個list包含dictionary所有的數據