Declaring a multi dimensional dictionary in python

Question

I need to make a two dimensional dictionary in python. e.g. new_dic[1][2] = 5

When I make new_dic = {}, and try to insert values, I get a <

Answer 1

For project, I needed to have 2D dict of class instances, where indeces are float numbers (coordinates). What I did, was to create 2D dict using default dict, and pass my class name as a type. For ex.:

class myCoordinates:
    def __init__(self, args)
    self.x = args[0]
    self.y = args[1]

and then when I tried to create dictionary:

table = mult_dim_dict(2, myCoordinates, (30, 30))

where function 'mult_dim_dict' defined as:

def mult_dim_dict(dim, dict_type, params):
    if dim == 1:
        if params is not None:
            return defaultdict(lambda: dict_type(params))
        else: 
            return defaultdict(dict_type)
    else:
        return defaultdict(lambda: mult_dim_dict(dim - 1, dict_type, params))

Note: you cannot pass multiple arguments, instead you can pass a tuple, containing all of your arguments. If your class, upon creation, does not need any variables to be passed, 3rd argument of function will be None:

class myCoors:
def __init__(self, tuple=(0, 0)):
    self.x, self.y = tuple

def printCoors(self):
    print("x = %d, y = %d" %(self.x, self.y))


def mult_dim_dict(dim, dict_type, params):
    if dim == 1:
        if params is not None:
            return defaultdict(lambda: dict_type(params))
        else:
            return defaultdict(dict_type)
    else:
        return defaultdict(lambda: mult_dim_dict(dim - 1, dict_type, params))

dict = mult_dim_dict(2, myCoors, None)
dict['3']['2'].x = 3
dict['3']['2'].y = 2

dict['3']['2'].printCoors()  # x = 3, y = 2 will be printed

dict = mult_dim_dict(2, myCoors, (30, 20))
dict['3']['2'].printCoors()  # x = 30, y = 20 will be printed