import unittest

class ArrayList(object):

def __init__(self):

self.list = [0] * 100 # init zeros in each cell

self.numElems = 0 # list starts empty

def append(self, x):

# check if there's enough room

if self.numElems >= len(self.list):

self._double_size()

self.list[self.numElems] = x

self.numElems += 1

def pop(self):

popped = self.list[-1]

self.list[-1] = 0

return popped

def insert(self, index, item):

if self.numElems == len(self.list):

self._double_size()

for i in range(self.numElems, index, -1):

self.list[i] = self.list[i-1]

self.list[index] = item

def _double_size(self):

# allocate a bigger internal list

newList = [0] * (2 * len(self.list))

# copy all the elements from the old list

i = 0

for i in range(len(self.list)):

newList[i] = self.list[i]

self.list = newList

def __str__(self):

s = ""

for i in range(self.numElems):

s += str(self.list[i])

if i != self.numElems: s += ','

return s

class Test_ArrayList(unittest.TestCase):

def setUp(self):

pass

def test_arraylist_one(self):

pass

if __name__ == '__name__':

unittest.main()