python 3.0 字典 key 排序

IDLE 3.0

>>> dic = {"aa":1,"bb":2,"ab":3}

>>> dic

{'aa': 1, 'ab': 3, 'bb': 2}

>>> for k in sorted(dic.keys()):

print (k)

aa

ab

bb

-----------------------------------------------

字典对象其实就是键-值对

下面是字典对象的添加，修改，删除

(修改与添加方法相同，当key值不存在的时候添加)

>>> dic["cc"] = 4

>>> dic

{'aa': 1, 'cc': 4, 'ab': 3, 'bb': 2}

>>> dic["bc"] = 5

>>> dic

{'aa': 1, 'cc': 4, 'ab': 3, 'bb': 2, 'bc': 5}

>>> dic["cc"] = 6

>>> dic

{'aa': 1, 'cc': 6, 'ab': 3, 'bb': 2, 'bc': 5}

>>> del dic["cc"]

>>> dic

{'aa': 1, 'ab': 3, 'bb': 2, 'bc': 5}