Python:对每个字典值执行操作

Question

在python 2.6中,我想对每个字典值执行一个操作,例如,我想为每个字典值乘以2.如何为此任务编写更少的代码？

Answer 1

# A nice one liner (edited to remove square brackets)   
my_dict.update((x, y*2) for x, y in my_dict.items())

Answer 2

# Multiply every value in my_dict by 2
for key in my_dict:    
    my_dict[key] *=  2

Answer 3

for key in d:
    d[key] = d[key] * 2

Answer 4

更新中的每个键my_dict：

my_dict.update({n: 2 * my_dict[n] for n in my_dict.keys()})