python中字典操作的总结（六种）

A={'a':7,'b':'happy'}
print(A['a'])
>>>7

A={'a':7,'b':'happy'}
A['c']=8
print(A)
>>>{'a': 7, 'b': 'happy', 'c': 8}

A={'a':7,'b':'happy'}
A['a']=8
print(A)
>>>{'a': 8, 'b': 'happy'}

A={'a': 7, 'b': 'happy', 'c': 8}
del A['c']
print(A)
>>>A={'a':7,'b':'happy'}

book={
    'number':'0',
    'name':'从入门到放弃',
    'author':'XXX',
    }
for x, y in book.items():   #1、同时取键值对
    print(x+':'+y)
    
for x in book.keys():       #2、只取键
    print(x)
 
for x in book.values():     #3、只取值
    print(x)

for x in set(book.values()):
    print(x)