[파이썬] 기초 다지기 dict(딕셔너리 함수)

 

dict 생성하기 (shell에서 실행하기)

shopping={}
shopping['apple']=2
shopping['pear']=3
shopping['hanrabong']=2
shopping['pine apple']=1
shopping

 

 

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dict 항목 읽기  (shell에서 실행하기)

shopping['apple']
shopping['pear']
shopping['mango']
shopping.get('mango','does not exist')
shopping.get('hanrabong','does not exist')

 

 

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dict 주요함수  (shell에서 실행하기)

shopping={'apple':2, 'pear':3, 'hanrabong':2, 'pine apple':1}
shopping.keys()
shopping.values()
shopping.items()

 

 

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dict 풀어내기 2 : unpacking operator *  (shell에서 실행하기)

 

1.

[*shopping.keys()]
[*shopping.values()]
[*shopping.items()]
*shopping.keys(),
*shopping.values(),
*shopping.items(),
{*shopping.keys()}
{*shopping.values()}
{*shopping.items()}
[*(i for i in range(3))] #리스트
*(i for i in range(3)), #튜플
{*(i for i in range(3))} #셋

 

 

2.

range(5)
[*range(5)]

 

 

 

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dict 와 for~in 문  (shell에서 실행하기)

shopping={'apple':2, 'pear':3, 'hanrabong':2, 'pine apple':1}
for key in shopping.keys():
    key
for value in shopping.values():
    value
for item in shopping.items():
    item   
for fruit,howMany in shopping.items():
    fruit,howMany

 

 

 

---

dict로 장보기 예제 1   (shell에서 실행하기)

shopping={'apple':2, 'pear':3, 'hanrabong':2, 'pine apple':1}
basket=[]
for fruit,howMany in shopping.items():
    fruit,howMany
    plasticBag=[]
    for _ in range(howMany):
        plasticBag.append(fruit)
    basket.append(plasticBag)
basket

 

 

 

---

dict로 장보기 2   (shell에서 실행하기)

shopping={'apple':2,'pear':3,'hanrabong':2,'pine apple':1}
basket=[]
for fruit,howMany in shopping.items():
    fruit,howMany
    basket.append([fruit]*howMany)

 

 

 

---

dict로 장보기 4  (shell에서 실행하기)

shopping={'apple':2,'pear':3,'hanrabong':2,'pine	apple':1}
basket=[]
while shopping:
    fruit,howMany=shopping.popitem()
    fruit,howMany
    basket.append([fruit]*howMany)
shopping
basket