python语法，字典中的值如何改变

用values把所有值遍历出来，然后怎么做运算，比如全部乘m，再更新字典

掌握字典的三个方法： .items() .keys() .values()

>>> dic = {1:1,2:2,3:3,4:4}
>>> m=4
>>> {i:j*m for i,j in dic.items()}
{1: 4, 2: 8, 3: 12, 4: 16}
>>> {i:j*m for i,j in zip(dic,dic.values())}
{1: 4, 2: 8, 3: 12, 4: 16}
>>> {i:j*m for i,j in zip(dic.keys(),dic.values())}
{1: 4, 2: 8, 3: 12, 4: 16}

字典d
for k,v in d.items():
d[k] = v*m

>>> dic = {1:1,2:2,3:3,4:4}
>>> m=2
>>> dic = {k:v*m for k,v in dic.items()}
>>> print(dic)
{1: 2, 2: 4, 3: 6, 4: 8}