Populating a list/array by index in Python?

Question

Is this possible:

myList = []

myList[12] = \'a\'
myList[22] = \'b\'
myList[32] = \'c\'
myList[42] = \'d\'

When I try, I get:

#         


        

Answer 1

Building on top of Triptych.. If you want a list of arbitrary dimensions

class dynamiclist(list):
    """ List not needing pre-initialization

    Example:
        l = dynamiclist()
        l[20][1] = 10
        l[21][1] = 20
    """

    def __setitem__(self, index, value):
        size = len(self)
        if index >= size:
            self.extend(dynamiclist() for _ in range(size, index + 1))

        list.__setitem__(self, index, value)

    def __getitem__(self, index):
        size = len(self)
        if index >= size:
            self.extend(dynamiclist() for _ in range(size, index + 1))  # allows dimensions > 1

        return list.__getitem__(self, index)

Example

l = dynamiclist()
l[20][1] = 10
l[21][1] = 20