[Python-ideas] PEP: Dict addition and subtraction

[Rhodri James]

On 21/03/2019 17:59, Rhodri James wrote:
> def process():
>      if time_to_do_thing1():
>          thing1(base_env + thing1_env_stuff + env_tweaks)
>      if time_to_do_thing2():
>          thing2(base_env + thing2_env_stuff + env_tweaks)
> 
> ...and so on.  The current syntax for doing this is a tad verbose:
> 
> def process():
>      if time_to_do_thing1():
>          env = base_env.copy()
>          env.update(thing1_env_stuff)
>          env.update(env_tweaks)
>          thing1(env)
>      del env
>      if time_to_do_thing2():
>          env = base_env.copy()
>          env.update(thing2_env_stuff)
>          env.update(env_tweaks)
>          thing2(env)
>          del env

Of course I forgot:

def process():
     if time_to_do_thing1():
         thing1({**base_env, **thing1_env_stuff, **env_tweaks})
     if time_to_do_thing2():
         thing2({**base_env, **thing2_env_stuff, **env_tweaks})

...which says something about how memorable that syntax is.

-- 
Rhodri James *-* Kynesim Ltd