python字典小知识

发布时间：2020-12-20 10:51:00 所属栏目：Python 来源：网络整理

导读：字典的小知识 dic = {"name": "tom","age": 23,"price": 110} # 01 ：提取键值 print ( " 1 " ,dic[ " name " ],type(dic[ " name " ])) # 1 tom class ‘str‘ print ( " 2 " ,dic.get( " name " )) # 1 tom print ( " 3 " ,dic.get( " n " ),type(dic.get(


　　　　　　　　　　　　　　　　　　字典的小知识
dic = {"name": "tom","age": 23,"price": 110}
# 01：提取键值

print("1>>",dic["name"],type(dic["name"]))  # 1>> tom    <class ‘str‘>
print("2>>",dic.get("name"))  # 1>> tom
print("3>>",dic.get("n"),type(dic.get("n")))  # 3>> None   <class ‘NoneType‘>

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# 02:判断键或值是否存在

1 print(‘name‘ in dic)   #True
2 print(‘tom‘ in dic)   #False
3 print(‘n‘ in dic)   #False

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# 03：设定指定字段值

dic[‘name‘]="jack"
print(dic)  #{‘name‘: ‘jack‘,‘age‘: 23,‘price‘: 110}
print(dic[‘name‘])  # jack

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# 04:访问所有键和值

# 1:提取所有的键
print(dic.keys())  # dict_keys([‘name‘,‘age‘,‘price‘])
print(type(dic.keys()))  # <class ‘dict_keys‘>

# 2：提取所有的值
print(dic.values())  # dict_values([‘tom‘,23,110])
print(type(dic.values()))  # <class ‘dict_values‘>

for key,value in dic.items():
    print(">>",key,value)

>> name tom
>> age 23
>> price 110

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（编辑：李大同）

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