【由淺入深學Python】字典（Dictionary）

字典采用鍵值對（key-value）的方式存儲，元素可以通過 key 訪問。字典是由花括號{ }括起來的包含，key : value 兩部分。

一、字典創建

#創建一個字典
dict1={
'name':'zhang','age':30,'city':'Beijing'}
print(dict1)

{‘name’: ‘zhang’, ‘age’: 30, ‘city’: ‘Beijing’}

二、常用操作

#獲取元素：通過Key獲取value值
dict1.get('age')

30

dict1.get('city')

‘Beijing’

增加元素

#給字典增加元素
dict1['gender']='Male'
print(dict1)

{‘name’: ‘zhang’, ‘age’: 30, ‘city’: ‘Beijing’, ‘gender’: ‘Male’}

修改元素

dict1['age']=35
print(dict1)

{‘name’: ‘zhang’, ‘age’: 35, ‘city’: ‘Beijing’, ‘gender’: ‘Male’}

刪除某個元素

#刪除某個元素
del dict1['gender']
print(dict1)

{‘name’: ‘zhang’, ‘age’: 35, ‘city’: ‘Beijing’}

#items() 
dict1.items()

dict_items([(‘name’, ‘zhang’), (‘age’, 35), (‘city’, ‘Beijing’)])

#遍歷字典
for key,value in dict1.items():
print(key+":",end="")
print(value)

name:zhang
age:35
city:Beijing

dict1.keys()

dict_keys([‘name’, ‘age’, ‘city’])

for key in dict1.keys():
print(key)

name
age
city