How to make a copy of chained dicts effectively and nicely?

[Lawrence D’Oliveiro]

On Tuesday, September 27, 2016 at 8:08:46 PM UTC+13, Nagy László Zsolt wrote:
> d1 = {'a':1, 'b':2}
> d2 = {'c':3, 'd':4}
> d3 = {'e':5, 'f':6}
> 
> Is there a version that is as effective as #3, but as clean and nice as #4?

dict(dict(d1, **d2), **d3)