Python Data Structures.ipynb

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  {
   "cell_type": "markdown",
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   },
   "source": [
    "# Data Structures Using Python"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "colab_type": "text",
    "id": "CIQkCKS25ugY"
   },
   "source": [
    "## Lists\n",
    "\n",
    "#### - **List properties:**  ordered,iterable, mutable, can contain multiple data types"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "colab_type": "text",
    "id": "Y0gkuky_5ugb"
   },
   "source": [
    "### Creating a list"
   ]
  },
  {
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   "execution_count": 0,
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    "outputId": "d3c88efa-c361-4435-aba7-ba6f3d241b21"
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[0, 1, 2, 3, 4] ['H', 'e', 'l', 'l', 'o']\n"
     ]
    }
   ],
   "source": [
    "list1 = [0,1,2,3,4]   # notice we use square brackets\n",
    "\n",
    "list2 = list('Hello')  # Passing a string to the list function gives a list of individual letters\n",
    "print(list1, list2)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "colab_type": "text",
    "id": "cH5U_raj5ugk"
   },
   "source": [
    "### Methods one can use with lists"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
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    "outputId": "306af4a8-fdfc-46fd-8da0-7c7aae3f8b3c"
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[0, 1, 2, 3, 4, 5]\n"
     ]
    }
   ],
   "source": [
    "list1.append(5)   # list.appen() is a method to add an element to the existing elements to a list\n",
    "print(list1)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
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    "outputId": "6e6fa208-707b-48f3-da3f-1ecdb5775fe0"
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[]\n"
     ]
    }
   ],
   "source": [
    "list1.clear()  # list.clear() removes all the elements of the list\n",
    "print(list1)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "UrsNr-_25ugw",
    "outputId": "104a4455-6935-4e3e-9edf-48a5029c7878"
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['H', 'e', 'l', 'l', 'o']\n"
     ]
    }
   ],
   "source": [
    "list3 = list2.copy()  # list.copy() returns a copy of the list\n",
    "print(list3)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "OjQwp4Qz5ug0",
    "outputId": "4dd69591-7924-4cc1-b5c3-599f530b783d"
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "2\n"
     ]
    }
   ],
   "source": [
    "number_of_l = list3.count('l')   # returns the number of times a certain value occurs\n",
    "print(number_of_l)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
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    "colab_type": "code",
    "id": "kFZKLDL45ug3",
    "outputId": "ebba3052-6ea9-435d-f9dd-e79274594063"
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['H', 'e', 'l', 'l', 'o', 'H', 'e', 'l', 'l', 'o']\n"
     ]
    }
   ],
   "source": [
    "list3.extend(list2)  # Extend one list using another list\n",
    "print(list3)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
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    "colab": {},
    "colab_type": "code",
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   "outputs": [
    {
     "data": {
      "text/plain": [
       "4"
      ]
     },
     "execution_count": 8,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "list3.index('o')   # list3.index() returns the index of an element in the list\n",
    "#If there are multiple entries of the same element multiple times, the method returns the first occurance"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
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    "outputId": "498bd490-1ca7-4109-9aea-bde964327c20"
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['H', 'e', 'l', 4, 'l', 'o', 'H', 'e', 'l', 'l', 'o']\n"
     ]
    }
   ],
   "source": [
    "list3.insert(3, 4)   # list.index() Insert an elemtent at a specific location\n",
    "print(list3)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
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    "outputId": "e2a4e4df-87f8-47c3-ba78-b57bef8e03e4"
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   "outputs": [
    {
     "data": {
      "text/plain": [
       "4"
      ]
     },
     "execution_count": 10,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "list3.pop(3)   # list.pop() removes an element and returns the element specified by its index location\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "sW70I4rN5uhK",
    "outputId": "da28ba36-668d-48f6-e6b6-04406996c6d7"
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['e', 'l', 'l', 'o', 'H', 'e', 'l', 'l', 'o']\n"
     ]
    }
   ],
   "source": [
    "list3.remove('H')   # list.remove() removes an element from the list. If there are multiple occurances, it removes the first one\n",
    "print(list3)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "b17ry4Ay5uhQ",
    "outputId": "3a24f304-219c-40cf-bcd1-d5c7275657f6"
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['o', 'l', 'l', 'e', 'H', 'o', 'l', 'l', 'e']\n"
     ]
    }
   ],
   "source": [
    "list3.reverse()  # list.reverse() reverses the list\n",
    "print(list3)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "V-pxxjHV5uhT",
    "outputId": "f7360225-98b2-401b-eb28-036ea2be9fec"
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['H', 'e', 'e', 'l', 'l', 'l', 'l', 'o', 'o']\n"
     ]
    }
   ],
   "source": [
    "list3.sort()  # list.sort() sorts the list in alphabetical order and incase of numbers, it sorts in ascending order\n",
    "print(list3)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "colab_type": "text",
    "id": "fIA2RtCF5uhX"
   },
   "source": [
    "### Indexing a list"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "HqTRcU-y5uhY",
    "outputId": "73134057-d0d4-4877-9398-8eb58772af70"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'e'"
      ]
     },
     "execution_count": 14,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "list3[2]   # Mention the index of the element to be extracted"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "MeWFH7tG5uhc",
    "outputId": "2761fa9d-8c98-4560-c72f-03350d10f794"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'o'"
      ]
     },
     "execution_count": 15,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "list3[-2]  # Python has negative indexing"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "gEwMYAyj5uhh",
    "outputId": "3336a3a6-7450-43a4-c490-ca88099b649b"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "['e', 'l', 'l']"
      ]
     },
     "execution_count": 16,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "list3[2:5]   # Extract a slice of the list from position 2 to 5. Notice that "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "IrkhdB7T5uhk",
    "outputId": "2967c89c-0a9c-45ca-bff5-cdf03b444f79"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "['H', 'e', 'e', 'l', 'l', 'l', 'l']"
      ]
     },
     "execution_count": 17,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "list3[:-2]  # All elements from the start until the 3rd element from the end"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "qxmQalNX5uhn",
    "outputId": "30bb5ac0-2406-4ffb-b5d3-dd526f1814c0"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "['H', 'e', 'l', 'l', 'o']"
      ]
     },
     "execution_count": 18,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "list3[::2] #The format is list[start : end : step] \n",
    "# Since we have given step as 2, it takes every element which is a multiple of 2"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "colab_type": "text",
    "id": "50XehpU45uhq"
   },
   "source": [
    "## Tuples\n",
    "\n",
    "- **Tuple properties:** ordered, iterable, immutable, can contain multiple data types\n",
    "- Like lists, but they don't change size"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "V3LxpBp85uht",
    "outputId": "48aecf22-ff4c-43f3-a3e0-36fed67dce47"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "(0, 1, 'two')"
      ]
     },
     "execution_count": 19,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# create a tuple directly\n",
    "digits = (0, 1, 'two')\n",
    "digits"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "sq-CNRJ95uhy",
    "outputId": "b707c5b2-684a-4a71-e261-f20e54681d0a"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "(0, 1, 'two')"
      ]
     },
     "execution_count": 20,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# create a tuple from a list\n",
    "digits = tuple([0, 1, 'two'])\n",
    "digits"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "--Mm_OUn5uh6"
   },
   "outputs": [],
   "source": [
    "# trailing comma is required to indicate it's a tuple\n",
    "zero = (0,)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "colab_type": "text",
    "id": "_IpgTYww5uiC"
   },
   "source": [
    "**Examine a tuple:**"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "phm8k-Nr5uiD",
    "outputId": "e0c097d4-3dc1-48f7-ae5e-0c56233bbdce"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "3"
      ]
     },
     "execution_count": 22,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "digits[2]\n",
    "\n",
    "len(digits)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "ociI86l55uiG",
    "outputId": "4ba45044-a238-48f1-b41e-0256250a0f43"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "1"
      ]
     },
     "execution_count": 23,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# counts the number of instances of that value\n",
    "digits.count(0)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "YOVVq5aa5uiI",
    "outputId": "2060b6b8-9976-4295-cda9-9c0f5c5be9cc"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "1"
      ]
     },
     "execution_count": 24,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# returns the index of the first instance of that value\n",
    "digits.index(1)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "colab_type": "text",
    "id": "f61jxNMU5uiM"
   },
   "source": [
    "**Modify a tuple:**"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "pHHnmuu85uiO",
    "outputId": "5e55747f-1241-4663-9a36-be320f717d42"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "(0, 1, 'two', 3, 4)"
      ]
     },
     "execution_count": 25,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# elements of a tuple cannot be modified (this would throw an error)\n",
    "# digits[2] = 2\n",
    "\n",
    "# concatenate tuples\n",
    "digits = digits + (3, 4)\n",
    "digits"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "colab_type": "text",
    "id": "SWnpj3Q_5uiS"
   },
   "source": [
    "**Other tuple operations:**"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "II3-3NoS5uiT",
    "outputId": "df40b20d-f02a-4f6f-fffd-04f784f94d81"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "(3, 4, 3, 4)"
      ]
     },
     "execution_count": 26,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# create a single tuple with elements repeated (also works with lists)\n",
    "(3, 4) * 2"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "NDNNIgHC5uiW",
    "outputId": "5a43ce51-abd8-4633-ea75-ae99ffde7586"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "[(10, 40), (20, 30), (20, 60)]"
      ]
     },
     "execution_count": 27,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# sort a list of tuples\n",
    "tens = [(20, 60), (10, 40), (20, 30)]\n",
    "sorted(tens)    # sorts by first element in tuple, then second element"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "mhBVxROx5uiY",
    "outputId": "b556dbf4-49f6-496d-bce9-476a53eb3670"
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "male\n",
      "10\n",
      "simpson\n"
     ]
    }
   ],
   "source": [
    "# tuple unpacking\n",
    "bart = ('male', 10, 'simpson')    # create a tuple\n",
    "(sex, age, surname) = bart        # assign three values at once\n",
    "print(sex)\n",
    "print(age)\n",
    "print(surname)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "colab_type": "text",
    "id": "FAHstTPZ5uib"
   },
   "source": [
    "##  Dictionaries\n",
    "\n",
    "- **Dictionary properties:** unordered, iterable, mutable, can contain multiple data types\n",
    "- Made of key-value pairs\n",
    "- Keys must be unique, and can be strings, numbers, or tuples\n",
    "- Values can be any type"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "colab_type": "text",
    "id": "yNm-dbOI5uic"
   },
   "source": [
    "### Creating a dictionary"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "sFTz4jGH5uie",
    "outputId": "befa1487-d2d9-4e17-ae19-1eef83940c9a"
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "{'Ed': [12, 'leader'], 'Edd': [11, 'smart'], 'Eddy': [10, 'kind']}\n"
     ]
    }
   ],
   "source": [
    "dict1 = {'Ed' : [12, 'leader'], 'Edd' : [ 11, 'smart'], 'Eddy' : [10, 'kind'] }\n",
    "# Notice we use flower brackets to declare a dictionary. Dictionaries have key-value pairs\n",
    "\n",
    "print(dict1) "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "sNEgSpPG5uil",
    "outputId": "fc5f722c-f576-4dcf-833c-722635f88044"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "{'Bubbles': [9, 'sweet'],\n",
       " 'Blossom': [10, 'leader'],\n",
       " 'Buttercup': [11, 'tomboy']}"
      ]
     },
     "execution_count": 30,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "dict2 = {}\n",
    "dict2['Bubbles'] = [9, 'sweet']\n",
    "dict2['Blossom'] = [10, 'leader']\n",
    "dict2['Buttercup'] = [11, 'tomboy']\n",
    "dict2"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "colab_type": "text",
    "id": "Kf-c19PS5uiq"
   },
   "source": [
    "### Indexing a dictionary"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "cMKP52gr5uir",
    "outputId": "1cfa033a-1afd-44f1-a2ff-3dee23e4e4a7"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "dict_keys(['Bubbles', 'Blossom', 'Buttercup'])"
      ]
     },
     "execution_count": 31,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "dict2.keys()    # dict.keys() to get all the keys of the dictionary"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "i9gXzaFu5uiw",
    "outputId": "4aaf1f60-3a65-426d-8d9a-18586760ff82"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "dict_values([[9, 'sweet'], [10, 'leader'], [11, 'tomboy']])"
      ]
     },
     "execution_count": 32,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "dict2.values()  # dict.values() to get all the values in the dictionary"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "9s3qQhn65ui0",
    "outputId": "34cb5fb8-3652-4fd6-9a1f-6fdc112dab84"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "[9, 'sweet']"
      ]
     },
     "execution_count": 33,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "dict2['Bubbles']    # To get values of a specific key"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "QNHAtYPB5ui2",
    "outputId": "00f4e470-cabc-4252-e9dc-eac4a1f932e7"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "{'dad': 'homer', 'mom': 'marge', 'size': 6}"
      ]
     },
     "execution_count": 34,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# convert a list of tuples into a dictionary\n",
    "list_of_tuples = [('dad', 'homer'), ('mom', 'marge'), ('size', 6)]\n",
    "family = dict(list_of_tuples)\n",
    "family"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "colab_type": "text",
    "id": "1GQnYQmq5ui5"
   },
   "source": [
    "**Examine a dictionary:**"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "rNJ9lWJA5ui6",
    "outputId": "0dd2a782-50fe-470e-9baf-245f1bf77ff0"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'homer'"
      ]
     },
     "execution_count": 35,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# pass a key to return its value\n",
    "family['dad']"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "GK2aYHDa5ui8",
    "outputId": "53e03959-a96a-4080-e860-4244c2dee722"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "3"
      ]
     },
     "execution_count": 36,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# return the number of key-value pairs\n",
    "len(family)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "FtdDnJDF5ui_",
    "outputId": "5aa04dfb-63b8-4408-cae3-a09ec83f38b6"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "True"
      ]
     },
     "execution_count": 37,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# check if key exists in dictionary\n",
    "'mom' in family"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "jDPysJP95ujD",
    "outputId": "c1945ee0-e311-4154-c458-2d29d942efd7"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "False"
      ]
     },
     "execution_count": 38,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# dictionary values are not checked\n",
    "'marge' in family"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "2dFPw36_5ujH",
    "outputId": "5adfe486-32a7-4171-8b95-e17b0fe27b8a"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "dict_keys(['dad', 'mom', 'size'])"
      ]
     },
     "execution_count": 39,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# returns a list of keys (Python 2) or an iterable view (Python 3)\n",
    "family.keys()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "1j0AZN885ujK",
    "outputId": "7306b322-8bca-4870-f07c-97e3cab96d0a"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "dict_values(['homer', 'marge', 6])"
      ]
     },
     "execution_count": 40,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# returns a list of values (Python 2) or an iterable view (Python 3)\n",
    "family.values()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "xKwLdWMG5ujM",
    "outputId": "1438b5de-021b-4110-afb4-e618c862ae5c"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "dict_items([('dad', 'homer'), ('mom', 'marge'), ('size', 6)])"
      ]
     },
     "execution_count": 41,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# returns a list of key-value pairs (Python 2) or an iterable view (Python 3)\n",
    "family.items()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "colab_type": "text",
    "id": "HSY8fLdJ5ujR"
   },
   "source": [
    "**Modify a dictionary (does not return the dictionary):**"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "tph-pIiY5ujS",
    "outputId": "8a2b2325-018a-4125-de8d-14373fa321d6"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "{'dad': 'homer', 'mom': 'marge', 'size': 6, 'cat': 'snowball'}"
      ]
     },
     "execution_count": 42,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# add a new entry\n",
    "family['cat'] = 'snowball'\n",
    "family"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "CMH9sRNf5ujX",
    "outputId": "6df55a9c-392d-4fe8-a060-d8f78a7a0749"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "{'dad': 'homer', 'mom': 'marge', 'size': 6, 'cat': 'snowball ii'}"
      ]
     },
     "execution_count": 43,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# edit an existing entry\n",
    "family['cat'] = 'snowball ii'\n",
    "family"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "Vml_RpvP5ujZ",
    "outputId": "5cced66d-e10b-4a12-d733-7f626c250172"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "{'dad': 'homer', 'mom': 'marge', 'size': 6}"
      ]
     },
     "execution_count": 44,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# delete an entry\n",
    "del family['cat']\n",
    "family"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "e4_HC6Yn5ujd",
    "outputId": "bfcc3d85-bc3b-4f3f-c5a1-32a09aae8588"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "{'dad': 'homer', 'mom': 'marge', 'size': 6, 'kids': ['bart', 'lisa']}"
      ]
     },
     "execution_count": 45,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# dictionary value can be a list\n",
    "family['kids'] = ['bart', 'lisa']\n",
    "family"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "hQpN40Wk5ujl",
    "outputId": "fb28c1ae-b8a2-4fde-cc1e-c8f1fc04d375"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'homer'"
      ]
     },
     "execution_count": 46,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# remove an entry and return the value\n",
    "family.pop('dad')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "f_1pzj7T5ujn",
    "outputId": "8e03283f-ccd6-472c-af19-ce5bcc04b9bb"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "{'mom': 'marge',\n",
       " 'size': 6,\n",
       " 'kids': ['bart', 'lisa'],\n",
       " 'baby': 'maggie',\n",
       " 'grandpa': 'abe'}"
      ]
     },
     "execution_count": 47,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# add multiple entries\n",
    "family.update({'baby':'maggie', 'grandpa':'abe'})\n",
    "family"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "colab_type": "text",
    "id": "YLKvnl9l5ujq"
   },
   "source": [
    "**Access values more safely with `get`:**"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "vp62LrkV5ujr",
    "outputId": "c47b4532-38ee-423e-886a-cd8c9262f308"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'marge'"
      ]
     },
     "execution_count": 48,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "family['mom']"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "l_F58smc5ujv",
    "outputId": "f5d53256-b30b-449b-9cbd-009839365bdf"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'marge'"
      ]
     },
     "execution_count": 49,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# equivalent to a dictionary lookup\n",
    "family.get('mom')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "9hupEicO5ujy"
   },
   "outputs": [],
   "source": [
    "# this would throw an error since the key does not exist\n",
    "# family['grandma']\n",
    "\n",
    "# return None if not found\n",
    "family.get('grandma')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "hbHaS2BF5uj0",
    "outputId": "f645795d-6691-4a58-af6d-384f3afb691f"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'not found'"
      ]
     },
     "execution_count": 51,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# provide a default return value if not found\n",
    "family.get('grandma', 'not found')"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "colab_type": "text",
    "id": "NuQ8aGKT5uj3"
   },
   "source": [
    "**Access a list element within a dictionary:**"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "7Ytd5k7I5uj4",
    "outputId": "62470b09-4942-418e-fb7e-0fdf4b75bffc"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "{'mom': 'marge',\n",
       " 'size': 6,\n",
       " 'kids': ['bart'],\n",
       " 'baby': 'maggie',\n",
       " 'grandpa': 'abe'}"
      ]
     },
     "execution_count": 52,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "family['kids'][0]\n",
    "\n",
    "family['kids'].remove('lisa')\n",
    "family"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "colab_type": "text",
    "id": "J05pr2c-5uj6"
   },
   "source": [
    "**String substitution using a dictionary:**"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "WAqlC9m05uj7",
    "outputId": "0f2120df-86ba-43c5-f662-ed7e6dda1cf8"
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "youngest child is maggie\n",
      "youngest child is maggie\n"
     ]
    }
   ],
   "source": [
    "print('youngest child is %(baby)s' % family)  # the old way \n",
    "print(f\"youngest child is {family['baby']}\")  # The new and easy way"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "colab_type": "text",
    "id": "XnflGDrr5uj9"
   },
   "source": [
    "##  Sets"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "colab_type": "text",
    "id": "4rZ3ZVNW5uj9"
   },
   "source": [
    "- **Set properties:** unordered, iterable, mutable, can contain multiple data types\n",
    "- Made of unique elements (strings, numbers, or tuples)\n",
    "- Like dictionaries, but with keys only (no values)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "PE6AjU2J5uj-",
    "outputId": "ad0cf993-829f-4aba-ab75-61c70ca648df"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "set()"
      ]
     },
     "execution_count": 54,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# create an empty set\n",
    "empty_set = set()\n",
    "empty_set"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "mJQg_9QG5ukI",
    "outputId": "870f8267-e39c-4edf-928c-f0257ad461d6"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "{'java', 'python', 'r'}"
      ]
     },
     "execution_count": 55,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# create a set directly\n",
    "languages = {'python', 'r', 'java'}\n",
    "languages"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "a2gY6yCy5ukK",
    "outputId": "a38ab4d7-b266-4376-b465-05b75dec140a"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "{'cobra', 'python', 'viper'}"
      ]
     },
     "execution_count": 56,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# create a set from a list\n",
    "snakes = set(['cobra', 'viper', 'python'])\n",
    "snakes"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "colab_type": "text",
    "id": "pEPq10N95ukM"
   },
   "source": [
    "**Examine a set:**"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "kzVE5-mR5ukQ",
    "outputId": "a567a70f-828c-42ec-b42d-910ee7b5dc35"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "3"
      ]
     },
     "execution_count": 57,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "    len(languages)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "jGJrkkkp5ukV",
    "outputId": "b40858cf-09ff-4f42-c9cd-ed6abfdbde66"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "True"
      ]
     },
     "execution_count": 58,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "'python' in languages"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "colab_type": "text",
    "id": "yMDhCSUo5uke"
   },
   "source": [
    "**Set operations:**"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "25UbxrE-5ukg",
    "outputId": "2525b738-63b0-44e5-d0c2-8af7d7415b69"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "{'python'}"
      ]
     },
     "execution_count": 59,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# intersection\n",
    "languages & snakes"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "XAZbhgYX5ukm",
    "outputId": "ff664032-5bc4-4da0-b9fb-6de72ae4ccf7"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "{'cobra', 'java', 'python', 'r', 'viper'}"
      ]
     },
     "execution_count": 60,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# union\n",
    "languages | snakes"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "Z6YSungS5ukr",
    "outputId": "9bca53ca-81c5-4c95-af88-c45acf54cbca"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "{'java', 'r'}"
      ]
     },
     "execution_count": 61,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# set difference\n",
    "languages - snakes"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "5EmnPWgF5ukw",
    "outputId": "662038d9-1535-4ba3-a685-0014657d8936"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "{'cobra', 'viper'}"
      ]
     },
     "execution_count": 62,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# set difference\n",
    "snakes - languages"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "colab_type": "text",
    "id": "QEIpOvrg5uk1"
   },
   "source": [
    "**Modify a set (does not return the set):**"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "vqnYICMk5uk2",
    "outputId": "4a78de41-6b62-412a-d736-73ca5f7b3e58"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "{'java', 'python', 'r', 'sql'}"
      ]
     },
     "execution_count": 63,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# add a new element\n",
    "languages.add('sql')\n",
    "languages"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "MI6uRLOO5uk5",
    "outputId": "823571e5-aab0-4fa1-c101-b4678386c9f1"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "{'java', 'python', 'r', 'sql'}"
      ]
     },
     "execution_count": 64,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# try to add an existing element (ignored, no error)\n",
    "languages.add('r')\n",
    "languages"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "q0_OaRWm5uk8",
    "outputId": "8b96ad66-139c-432e-c138-45b1c0bbeda7"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "{'python', 'r', 'sql'}"
      ]
     },
     "execution_count": 65,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# remove an element\n",
    "languages.remove('java')\n",
    "languages"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "g2Yw-4JN5uk-"
   },
   "outputs": [],
   "source": [
    "# try to remove a non-existing element (this would throw an error)\n",
    "# languages.remove('c')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "rpAuug6Y5ulA",
    "outputId": "408d760f-1559-41bd-f28a-7365c0ca4533"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "{'python', 'r', 'sql'}"
      ]
     },
     "execution_count": 67,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# remove an element if present, but ignored otherwise\n",
    "languages.discard('c')\n",
    "languages"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "O6U-Tf2f5ulD",
    "outputId": "d05a660b-e16b-4539-8816-ba330a1bbe4a"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'python'"
      ]
     },
     "execution_count": 68,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# remove and return an arbitrary element\n",
    "languages.pop()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "xu6UCNTw5ulH",
    "outputId": "951a4e71-6158-47b0-de8c-6788dbb5e797"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "set()"
      ]
     },
     "execution_count": 69,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# remove all elements\n",
    "languages.clear()\n",
    "languages"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "UkTQI4QQ5ulL",
    "outputId": "785e236f-d87c-4b74-8364-e9407cf4ddb1"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "{'go', 'spark'}"
      ]
     },
     "execution_count": 70,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# add multiple elements (can also pass a set)\n",
    "languages.update(['go', 'spark'])\n",
    "languages"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "colab_type": "text",
    "id": "i4QmQ62x5ulQ"
   },
   "source": [
    "**Get a sorted list of unique elements from a list:**"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 0,
   "metadata": {
    "colab": {},
    "colab_type": "code",
    "id": "rqo9O0iO5ulV",
    "outputId": "bfef7a33-0fe3-4ec1-fbd6-ee276c972c4d"
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "[0, 1, 2, 9]"
      ]
     },
     "execution_count": 71,
     "metadata": {
      "tags": []
     },
     "output_type": "execute_result"
    }
   ],
   "source": [
    "sorted(set([9, 0, 2, 1, 0]))"
   ]
  }
 ],
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