Dynamic Array (Vector)

dynamic_array.py

import ctypes

class DynamicArray:
    def __init__(self):
        self.capacity = 1
        self.size = 0
        self.array = self._make_array(self.capacity)

    def append(self, elt):
        if self.size == self.capacity:
            self._resize(2 * self.capacity)
        self.array[self.size] = elt
        self.size += 1

    def _resize(self, capacity):
        new_array = (capacity * ctypes.py_object)()
        for k in range(self.size):
            new_array[k] = self.array[k]
        self.array = new_array
        self.capacity = capacity

    def _make_array(self, capacity):
        return (capacity * ctypes.py_object)()         
    def __len__(self):
        return self.size

    def __getitem__(self, index):
        if 0 <= index < self.size:
            return self.array[index]
        raise IndexError("Out of bounds")

    def __setitem__(self, index, value):
        if not 0 <= index < self.size:
            self.array[index] = value
            return
        raise IndexError("Out of bounds")

 
arr = DynamicArray()
arr.append(1)
arr.append(2)