字典簡介

字典是鍵值儲存的示例，也稱為 Python 中的對映。它允許你通過引用鍵來儲存和檢索元素。由於字典是由金鑰引用的，因此它們具有非常快速的查詢。由於它們主要用於按鍵引用專案，因此它們不會被排序。

創造一個字典

字典可以通過多種方式啟動：

文字語法

d = {}                        # empty dict
d = {'key': 'value'}          # dict with initial values

Python 3.x >= 3.5

# Also unpacking one or multiple dictionaries with the literal syntax is possible

# makes a shallow copy of otherdict
d = {**otherdict}
# also updates the shallow copy with the contents of the yetanotherdict.
d = {**otherdict, **yetanotherdict}

dict 理解

d = {k:v for k,v in [('key', 'value',)]}

另見： 理解

內建類：dict()

d = dict()                    # emtpy dict
d = dict(key='value')         # explicit keyword arguments
d = dict([('key', 'value')])  # passing in a list of key/value pairs
# make a shallow copy of another dict (only possible if keys are only strings!)
d = dict(**otherdict)         

修改字典

要將項新增到字典，只需建立一個帶有值的新鍵：

d['newkey'] = 42

也可以新增 list 和 dictionary 作為值：

d['new_list'] = [1, 2, 3]
d['new_dict'] = {'nested_dict': 1}

要刪除專案，請從字典中刪除金鑰：

del d['newkey']