[Tutor] which of these is more efficient?

[Mark Lawrence]

On 19/08/2019 00:55, nathan tech wrote:
> Hi there,
> 
> So I am running over some coding ideas in my head for creating a map for
> a game.
> 
> This map would expand based on how far the user explores.
> 
> I figure there are two ways to do this:
> 
> 1: the list method:
> 
> map=[]
> 
> for x in range(3):
> 
>    temp=[]
> 
>    for y in range(3):
> 
>     temp.append(default_grid_format)
> 
>    map.append(temp)
> 
> 
> then when ever the user explores a square not on the current map, it
> would do this:
> 
> for x in range(len(map)):
> 
>    map[x].append(default_grid_format)
> 
> temp=[]
> 
> for x in range(len(map[0])):
> 
>    temp.append(default_grid_format)
> 
> map.append(temp)
> 
> Obviously, though, this creates a lot of data for squares that are still
> ultimately unexplored.
> 
> So here was my other idea:
> 
> 
> 2. the dictionary method:
> 
> map={}
> 
> for x in range(3):
> 
>    for y in range(3):
> 
>     key=str(x)+":"+str(y)
> 
>     map[key]=default_grid_format
> 
> 
> Then when user explores new square do:
> 
> key=str(player_x)+":"+str(player_y)
> 
> map[key]=default_grid_format
> 
> 
> Is this an efficient method compared to 1?
> 
> Is it, code wise, sound logic?
> 
> 
> 
> I guess I'm just looking for a second opinion from experienced peoples.
> 
> thanks everyone.
> 
> Nathan
> 

Quite frankly I've no idea as in 19 years of using Python my gut has 
never once been correct about code efficiency, so I suggest that you try 
it and see.  Start with https://docs.python.org/3/library/timeit.html. 
Of course this assumes that you need to do this in the first place :)

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence