Intro to lists.ipynb

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   "cell_type": "code",
   "execution_count": 2,
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   "source": [
    "a=[3,10,-1]"
   ]
  },
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   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
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     "name": "stdout",
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     "text": [
      "[3, 10, -1]\n"
     ]
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   "source": [
    "print(a)"
   ]
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   "execution_count": 4,
   "metadata": {},
   "outputs": [],
   "source": [
    "a.append(1)"
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   "outputs": [
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     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[3, 10, -1, 1]\n"
     ]
    }
   ],
   "source": [
    "print(a)"
   ]
  },
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   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [],
   "source": [
    "a.append(\"hello\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[3, 10, -1, 1, 'hello']\n"
     ]
    }
   ],
   "source": [
    "print(a)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [],
   "source": [
    "a.append([1,2])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[3, 10, -1, 1, 'hello', [1, 2]]\n"
     ]
    }
   ],
   "source": [
    "print(a)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[3, 10, -1, 1, 'hello']\n"
     ]
    }
   ],
   "source": [
    "#to delete a item\n",
    "a.pop()\n",
    "print(a)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[3, 10, -1, 1]\n"
     ]
    }
   ],
   "source": [
    "#pop deletes the last item in the list\n",
    "a.pop()\n",
    "print(a)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "3"
      ]
     },
     "execution_count": 12,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "#to retrieve an element from the list by its index value\n",
    "a[0] # gives element 0 in list a;it doesnt work in pycharm editor"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 13,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "3\n"
     ]
    }
   ],
   "source": [
    "#for pycharm editor\n",
    "print(a[0])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "metadata": {},
   "outputs": [],
   "source": [
    "#changing value at a particular index; for example if you want 3 to be changed to 100\n",
    "\n",
    "a[0]=100 \n",
    "#0th element of a which contained 3 is assigned 100 "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 15,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[100, 10, -1, 1]\n"
     ]
    }
   ],
   "source": [
    "print(a)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 24,
   "metadata": {},
   "outputs": [],
   "source": [
    "b=[\"banana\",\"apple\",\"microsoft\"]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 25,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['banana', 'apple', 'microsoft']\n"
     ]
    }
   ],
   "source": [
    "print(b)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 26,
   "metadata": {},
   "outputs": [],
   "source": [
    "temp=b[0]\n",
    "b[0]=b[2]\n",
    "b[2]=temp"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 27,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['microsoft', 'apple', 'banana']\n"
     ]
    }
   ],
   "source": [
    "print(b)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 28,
   "metadata": {},
   "outputs": [],
   "source": [
    "#a shortcut method to swap to elements...\n",
    "\n",
    "b[0],b[2]=b[2],b[0]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 29,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['banana', 'apple', 'microsoft']\n"
     ]
    }
   ],
   "source": [
    "print(b)"
   ]
  }
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