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Python基礎--字典(dictionary)

字典 dictionary

1.字典的定義,鍵唯一,值隨意

dic={key0:value0,key1:value1}

2.輸出

print(dic[key0])
>>:value0

3.遍歷字典
3.1keys()遍歷字典中的key

dic={‘name‘:‘zhangsan‘,‘age‘:20}
for k in dic.keys():
    print(k)
>>:
name
age             

3.2values()遍歷字典中的value

dic={‘name‘:‘zhangsan‘,‘age‘:20}
for v in dic.values():
    print(v)
>>:
zhangsan
20

3.3items()遍歷字典中的key,value

dic={‘name‘:‘zhangsan‘,‘age‘:20}
for k,v in dic.items():
    print(k+‘:‘+str(v))
>>:
name:zhangsan
age:20      

4.字典插入元素

dic={‘name‘:‘zhangsan‘,‘age‘:20}
dic[‘job‘]=‘python‘
print(dic)
>>:
{‘name‘: ‘zhangsan‘, ‘age‘: 20, ‘job‘: ‘python‘}

5.根據鍵修改值

dic={‘name‘:‘zhangsan‘,‘age‘:20}
dic[‘name‘]=‘lisi‘
print(dic)
>>:
{‘name‘: ‘lisi‘, ‘age‘: 20}

6.pop()刪除字典中的元素

dic={‘name‘:‘zhangsan‘,‘age‘:20}
dic.pop(‘name‘)
print(dic)
>>:
{‘age‘: 20}

7.判讀元素是否在字典中:

dic={‘name‘:‘zhangsan‘,‘age‘:20}
tmp=‘name‘
if tmp in dic:#和 if  tmp in dic.keys()相同:
    print("%s in dic" %tmp)
#判斷元組是否在值中
if tmp in dic.values():
    print("%s in dic" %tmp)

Python基礎--字典(dictionary)