specific function to return variables for create a class by entering specific name from a List in python?

Question

I would like to find a function that can return a specific object of a specific list in Python. For example if I have a structure like this :

obj_list = [ "A" , "B" , "C" ]

class ex:
   def __init__(self, var1, var2, var3):
      self.var1 = var1
      self.var2 = var2
      self.var3 = var3

def find(key):
    if key == "A"
       return ex(1, 2, 3)
    if key == "B"
       return ex(2,3,4)
    if key == "C"
       return ex(4,5,6)

exists in python a specific function that allows me to do this operation without using an indefinite set of if ? because in my case imagine that I have a list of element lit_obj much longer I would like to avoid writing many ifs and make the code cleaner enclosing everything in a single function. In typescript for example I can use the record function<K,T> to do this operation, is there a specific in python ? thanks for the help

example in TS:

type MainnetPoolKey = "A" | "B" | "C" ;

interface Pool {
  var1: number;
  var2: number;
  var3: number;
}

const MainnetPools: Record<MainnetPoolKey, Pool> = {
  A: {
    var1: 86498781,
    var2: 0
    var3: 686505742,
  },
  B: {
    var1: 686500029,
    var2: 31566704,
    var3: 86508050,
  },
  C: {
    var1: 86500844,
    var2: 312769,
    var3: 509463,
}
}

How would that magic function know with which parameters it should call ex()? — Sören, Jul 06 '22 at 13:38
I don't see how typescript's `Record` would be used to implement your `find`; could you provide an example? — Scott Hunter, Jul 06 '22 at 13:46
Record if I for example use Record I can have the find return immediately — Simospa, Jul 06 '22 at 13:51
I add an example above, I would like to obtain in python the same result — Simospa, Jul 06 '22 at 13:56
In Python this would be done with a dictionary: `{'A': (1,2,3), 'B': (4,5,6)}` for example. Then you could do `ex(*theDict[key])` to turn the dict value into function parameters. — jasonharper, Jul 06 '22 at 14:01
ok thanks man this is how I do that, but I'm only searching for a function that can do it in a clean way, but everyone attack me for no reason... — Simospa, Jul 06 '22 at 14:03

score 1 · Answer 1 · answered Jul 06 '22 at 14:27

I don't know how Record function of typescript works, but I can give you what you want.

solution

Just save everything into dictionary and loading it from function does what you want.

presets = {
    "A": {
        "var1": 1,
        "var2": 2,
        "var3": 3
    },
    "B": {
        "var1": 2,
        "var2": 3,
        "var3": 4
    },
    "C": {
        "var1": 4,
        "var2": 5,
        "var3": 6
    }
}

class ex:
    def __init__(self, var1, var2, var3):
        self.var1 = var1
        self.var2 = var2
        self.var3 = var3

def find(key):
    return ex(**presets[key])

a = find("A")
print(a.var1, a.var2, a.var3) # 1 2 3

** in find function means unpacking dictionary into parameters. Looking at What does ** (double star/asterisk) and * (star/asterisk) do for parameters? will help.

specific function to return variables for create a class by entering specific name from a List in python?

1 Answers1

solution