PY0101EN-2-2-Lists.ipynb

{"cells":[{"cell_type":"markdown","metadata":{},"source":["<center>\n","    <img src=\"https://cf-courses-data.s3.us.cloud-object-storage.appdomain.cloud/IBMDeveloperSkillsNetwork-PY0101EN-SkillsNetwork/IDSNlogo.png\" width=\"300\" alt=\"cognitiveclass.ai logo\"  />\n","</center>\n","\n","# Lists in Python\n","\n","Estimated time needed: **15** minutes\n","\n","## Objectives\n","\n","After completing this lab you will be able to:\n","\n","*   Perform list operations in Python, including indexing, list manipulation, and copy/clone list.\n"]},{"cell_type":"markdown","metadata":{},"source":["<h2>Table of Contents</h2>\n","<div class=\"alert alert-block alert-info\" style=\"margin-thttps://op/?utm_medium=Exinfluencer&utm_source=Exinfluencer&utm_https://co/?utm_medium=Exinfluencer&utm_source=Exinfluencer&utm_content=000026UJ&utm_term=10006555&utm_id=NA-SkillsNetwork-Channel-SkillsNetworkCoursesIBMDeveloperSkillsNetworkPY0101ENSkillsNetwork19487395-2021-01-01ntent=000026UJ&utm_term=10006555&utm_id=NA-SkillsNetwork-Channel-SkillsNetworkCoursesIBMDeveloperSkillsNetworkPY0101ENSkillsNetwork19487395-2021-01-01: 20px\">\n","    <ul>\n","        <li>\n","            <a href=\"https://#dataset\">About the Dataset</a>\n","        </li>\n","        <li>\n","            <a href=\"https://#list\">Lists</a>\n","            <ul>\n","                <li><a href=\"https://index/?utm_medium=Exinfluencer&utm_source=Exinfluencer&utm_https://content/?utm_medium=Exinfluencer&utm_source=Exinfluencer&utm_content=000026UJ&utm_term=10006555&utm_id=NA-SkillsNetwork-Channel-SkillsNetworkCoursesIBMDeveloperSkillsNetworkPY0101ENSkillsNetwork19487395-2021-01-01=000026UJ&utm_term=10006555&utm_id=NA-SkillsNetwork-Channel-SkillsNetworkCoursesIBMDeveloperSkillsNetworkPY0101ENSkillsNetwork19487395-2021-01-01\">Indexing</a></li>\n","                <li><a href=\"content\">List Content</a></li>\n","                <li><a href=\"op\">List Operations</a></li>\n","                <li><a href=\"co\">Copy and Clone List</a></li>\n","            </ul>\n","        </li>\n","        <li>\n","            <a href=\"https://#quiz\">Quiz on Lists</a>\n","        </li>\n","    </ul>\n","\n","</div>\n","\n","<hr>\n"]},{"cell_type":"markdown","metadata":{},"source":["<h2 id=\"#dataset\">About the Dataset</h2>\n"]},{"cell_type":"markdown","metadata":{},"source":["Imagine you received album recommendations from your friends and compiled all of the recommandations into a table, with specific information about each album.\n","\n","The table has one row for each movie and several columns:\n","\n","*   **artist** - Name of the artist\n","*   **album** - Name of the album\n","*   **released_year** - Year the album was released\n","*   **length_min_sec** - Length of the album (hours,minutes,seconds)\n","*   **genre** - Genre of the album\n","*   **music_recording_sales_millions** - Music recording sales (millions in USD) on [SONG://DATABASE](http://www.song-database.com/?utm_medium=Exinfluencer&utm_source=Exinfluencer&utm_content=000026UJ&utm_term=10006555&utm_id=NA-SkillsNetwork-Channel-SkillsNetworkCoursesIBMDeveloperSkillsNetworkPY0101ENSkillsNetwork19487395-2021-01-01)\n","*   **claimed_sales_millions** - Album's claimed sales (millions in USD) on [SONG://DATABASE](http://www.song-database.com/?utm_medium=Exinfluencer&utm_source=Exinfluencer&utm_content=000026UJ&utm_term=10006555&utm_id=NA-SkillsNetwork-Channel-SkillsNetworkCoursesIBMDeveloperSkillsNetworkPY0101ENSkillsNetwork19487395-2021-01-01)\n","*   **date_released** - Date on which the album was released\n","*   **soundtrack** - Indicates if the album is the movie soundtrack (Y) or (N)\n","*   **rating_of_friends** - Indicates the rating from your friends from 1 to 10\n","\n","<br>\n","<br>\n","\n","The dataset can be seen below:\n","\n","<font size=\"1\">\n","<table font-size:xx-small>\n","  <tr>\n","    <th>Artist</th>\n","    <th>Album</th> \n","    <th>Released</th>\n","    <th>Length</th>\n","    <th>Genre</th> \n","    <th>Music recording sales (millions)</th>\n","    <th>Claimed sales (millions)</th>\n","    <th>Released</th>\n","    <th>Soundtrack</th>\n","    <th>Rating (friends)</th>\n","  </tr>\n","  <tr>\n","    <td>Michael Jackson</td>\n","    <td>Thriller</td> \n","    <td>1982</td>\n","    <td>00:42:19</td>\n","    <td>Pop, rock, R&B</td>\n","    <td>46</td>\n","    <td>65</td>\n","    <td>30-Nov-82</td>\n","    <td></td>\n","    <td>10.0</td>\n","  </tr>\n","  <tr>\n","    <td>AC/DC</td>\n","    <td>Back in Black</td> \n","    <td>1980</td>\n","    <td>00:42:11</td>\n","    <td>Hard rock</td>\n","    <td>26.1</td>\n","    <td>50</td>\n","    <td>25-Jul-80</td>\n","    <td></td>\n","    <td>8.5</td>\n","  </tr>\n","    <tr>\n","    <td>Pink Floyd</td>\n","    <td>The Dark Side of the Moon</td> \n","    <td>1973</td>\n","    <td>00:42:49</td>\n","    <td>Progressive rock</td>\n","    <td>24.2</td>\n","    <td>45</td>\n","    <td>01-Mar-73</td>\n","    <td></td>\n","    <td>9.5</td>\n","  </tr>\n","    <tr>\n","    <td>Whitney Houston</td>\n","    <td>The Bodyguard</td> \n","    <td>1992</td>\n","    <td>00:57:44</td>\n","    <td>Soundtrack/R&B, soul, pop</td>\n","    <td>26.1</td>\n","    <td>50</td>\n","    <td>25-Jul-80</td>\n","    <td>Y</td>\n","    <td>7.0</td>\n","  </tr>\n","    <tr>\n","    <td>Meat Loaf</td>\n","    <td>Bat Out of Hell</td> \n","    <td>1977</td>\n","    <td>00:46:33</td>\n","    <td>Hard rock, progressive rock</td>\n","    <td>20.6</td>\n","    <td>43</td>\n","    <td>21-Oct-77</td>\n","    <td></td>\n","    <td>7.0</td>\n","  </tr>\n","    <tr>\n","    <td>Eagles</td>\n","    <td>Their Greatest Hits (1971-1975)</td> \n","    <td>1976</td>\n","    <td>00:43:08</td>\n","    <td>Rock, soft rock, folk rock</td>\n","    <td>32.2</td>\n","    <td>42</td>\n","    <td>17-Feb-76</td>\n","    <td></td>\n","    <td>9.5</td>\n","  </tr>\n","    <tr>\n","    <td>Bee Gees</td>\n","    <td>Saturday Night Fever</td> \n","    <td>1977</td>\n","    <td>1:15:54</td>\n","    <td>Disco</td>\n","    <td>20.6</td>\n","    <td>40</td>\n","    <td>15-Nov-77</td>\n","    <td>Y</td>\n","    <td>9.0</td>\n","  </tr>\n","    <tr>\n","    <td>Fleetwood Mac</td>\n","    <td>Rumours</td> \n","    <td>1977</td>\n","    <td>00:40:01</td>\n","    <td>Soft rock</td>\n","    <td>27.9</td>\n","    <td>40</td>\n","    <td>04-Feb-77</td>\n","    <td></td>\n","    <td>9.5</td>\n","  </tr>\n","</table></font>\n"]},{"cell_type":"markdown","metadata":{},"source":["<hr>\n"]},{"cell_type":"markdown","metadata":{},"source":["<h2 id=\"list\">Lists</h2>\n"]},{"cell_type":"markdown","metadata":{},"source":["<h3 id=\"index\">Indexing</h3>\n"]},{"cell_type":"markdown","metadata":{},"source":["We are going to take a look at lists in Python. A list is a sequenced collection of different objects such as integers, strings, and even other lists as well. The address of each element within a list is called an <b>index</b>. An index is used to access and refer to items within a list.\n"]},{"cell_type":"markdown","metadata":{},"source":["<img src=\"https://cf-courses-data.s3.us.cloud-object-storage.appdomain.cloud/IBMDeveloperSkillsNetwork-PY0101EN-SkillsNetwork/labs/Module%202/images/ListsIndex.png\" width=\"1000\" />\n"]},{"cell_type":"markdown","metadata":{},"source":["To create a list, type the list within square brackets <b>\\[ ]</b>, with your content inside the parenthesis and separated by commas. Let’s try it!\n"]},{"cell_type":"code","execution_count":null,"metadata":{},"outputs":[],"source":["# Create a list\n","\n","L = [\"Michael Jackson\", 10.1, 1982]\n","L"]},{"cell_type":"markdown","metadata":{},"source":["We can use negative and regular indexing with a list:\n"]},{"cell_type":"markdown","metadata":{},"source":["<img src=\"https://cf-courses-data.s3.us.cloud-object-storage.appdomain.cloud/IBMDeveloperSkillsNetwork-PY0101EN-SkillsNetwork/labs/Module%202/images/ListsNeg.png\" width=\"1000\" />\n"]},{"cell_type":"code","execution_count":null,"metadata":{},"outputs":[],"source":["# Print the elements on each index\n","\n","print('the same element using negative and positive indexing:\\n Postive:',L[0],\n","'\\n Negative:' , L[-3]  )\n","print('the same element using negative and positive indexing:\\n Postive:',L[1],\n","'\\n Negative:' , L[-2]  )\n","print('the same element using negative and positive indexing:\\n Postive:',L[2],\n","'\\n Negative:' , L[-1]  )"]},{"cell_type":"markdown","metadata":{},"source":["<h3 id=\"content\">List Content</h3>\n"]},{"cell_type":"markdown","metadata":{},"source":["Lists can contain strings, floats, and integers. We can nest other lists, and we can also nest tuples and other data structures. The same indexing conventions apply for nesting:\n"]},{"cell_type":"code","execution_count":null,"metadata":{},"outputs":[],"source":["# Sample List\n","\n","[\"Michael Jackson\", 10.1, 1982, [1, 2], (\"A\", 1)]"]},{"cell_type":"markdown","metadata":{},"source":["<h3 id=\"op\">List Operations</h3>\n"]},{"cell_type":"markdown","metadata":{},"source":["We can also perform slicing in lists. For example, if we want the last two elements, we use the following command:\n"]},{"cell_type":"code","execution_count":null,"metadata":{},"outputs":[],"source":["# Sample List\n","\n","L = [\"Michael Jackson\", 10.1,1982,\"MJ\",1]\n","L"]},{"cell_type":"markdown","metadata":{},"source":["<img src=\"https://cf-courses-data.s3.us.cloud-object-storage.appdomain.cloud/IBMDeveloperSkillsNetwork-PY0101EN-SkillsNetwork/labs/Module%202/images/ListsSlice.png\" width=\"1000\">\n"]},{"cell_type":"code","execution_count":null,"metadata":{},"outputs":[],"source":["# List slicing\n","\n","L[3:5]"]},{"cell_type":"markdown","metadata":{},"source":["We can use the method <code>extend</code> to add new elements to the list:\n"]},{"cell_type":"code","execution_count":null,"metadata":{},"outputs":[],"source":["# Use extend to add elements to list\n","\n","L = [ \"Michael Jackson\", 10.2]\n","L.extend(['pop', 10])\n","L"]},{"cell_type":"markdown","metadata":{},"source":["Another similar method is <code>append</code>. If we apply <code>append</code> instead of <code>extend</code>, we add one element to the list:\n"]},{"cell_type":"code","execution_count":null,"metadata":{},"outputs":[],"source":["# Use append to add elements to list\n","\n","L = [ \"Michael Jackson\", 10.2]\n","L.append(['pop', 10])\n","L"]},{"cell_type":"markdown","metadata":{},"source":["Each time we apply a method, the list changes. If we apply <code>extend</code> we add two new elements to the list. The list <code>L</code> is then modified by adding two new elements:\n"]},{"cell_type":"code","execution_count":null,"metadata":{},"outputs":[],"source":["# Use extend to add elements to list\n","\n","L = [ \"Michael Jackson\", 10.2]\n","L.extend(['pop', 10])\n","L"]},{"cell_type":"markdown","metadata":{},"source":["If we append the list  <code>\\['a','b']</code> we have one new element consisting of a nested list:\n"]},{"cell_type":"code","execution_count":null,"metadata":{},"outputs":[],"source":["# Use append to add elements to list\n","\n","L.append(['a','b'])\n","L"]},{"cell_type":"markdown","metadata":{},"source":["As lists are mutable, we can change them. For example, we can change the first element as follows:\n"]},{"cell_type":"code","execution_count":null,"metadata":{},"outputs":[],"source":["# Change the element based on the index\n","\n","A = [\"disco\", 10, 1.2]\n","print('Before change:', A)\n","A[0] = 'hard rock'\n","print('After change:', A)"]},{"cell_type":"markdown","metadata":{},"source":["We can also delete an element of a list using the <code>del</code> command:\n"]},{"cell_type":"code","execution_count":null,"metadata":{},"outputs":[],"source":["# Delete the element based on the index\n","\n","print('Before change:', A)\n","del(A[0])\n","print('After change:', A)"]},{"cell_type":"markdown","metadata":{},"source":["We can convert a string to a list using <code>split</code>.  For example, the method <code>split</code> translates every group of characters separated by a space into an element in a list:\n"]},{"cell_type":"code","execution_count":null,"metadata":{},"outputs":[],"source":["# Split the string, default is by space\n","\n","'hard rock'.split()"]},{"cell_type":"markdown","metadata":{},"source":["We can use the split function to separate strings on a specific character which we call a **delimiter**. We pass the character we would like to split on into the argument, which in this case is a comma.  The result is a list, and each element corresponds to a set of characters that have been separated by a comma:\n"]},{"cell_type":"code","execution_count":null,"metadata":{},"outputs":[],"source":["# Split the string by comma\n","\n","'A,B,C,D'.split(',')"]},{"cell_type":"markdown","metadata":{},"source":["<h3 id=\"co\">Copy and Clone List</h3>\n"]},{"cell_type":"markdown","metadata":{},"source":["When we set one variable <b>B</b> equal to <b>A</b>, both <b>A</b> and <b>B</b> are referencing the same list in memory:\n"]},{"cell_type":"code","execution_count":null,"metadata":{},"outputs":[],"source":["# Copy (copy by reference) the list A\n","\n","A = [\"hard rock\", 10, 1.2]\n","B = A\n","print('A:', A)\n","print('B:', B)"]},{"cell_type":"markdown","metadata":{},"source":["<img src=\"https://cf-courses-data.s3.us.cloud-object-storage.appdomain.cloud/IBMDeveloperSkillsNetwork-PY0101EN-SkillsNetwork/labs/Module%202/images/ListsRef.png\" width=\"1000\" align=\"center\">\n"]},{"cell_type":"markdown","metadata":{},"source":["Initially, the value of the first element in <b>B</b> is set as \"hard rock\". If we change the first element in <b>A</b> to <b>\"banana\"</b>, we get an unexpected side effect.  As <b>A</b> and <b>B</b> are referencing the same list, if we change list <b>A</b>, then list <b>B</b> also changes. If we check the first element of <b>B</b> we get \"banana\" instead of \"hard rock\":\n"]},{"cell_type":"code","execution_count":null,"metadata":{},"outputs":[],"source":["# Examine the copy by reference\n","\n","print('B[0]:', B[0])\n","A[0] = \"banana\"\n","print('B[0]:', B[0])"]},{"cell_type":"markdown","metadata":{},"source":["This is demonstrated in the following figure:\n"]},{"cell_type":"markdown","metadata":{},"source":["<img src = \"https://cf-courses-data.s3.us.cloud-object-storage.appdomain.cloud/IBMDeveloperSkillsNetwork-PY0101EN-SkillsNetwork/labs/Module%202/images/ListsRefGif.gif\" width=\"1000\" />\n"]},{"cell_type":"markdown","metadata":{},"source":["You can clone list **A** by using  the following syntax:\n"]},{"cell_type":"code","execution_count":null,"metadata":{},"outputs":[],"source":["# Clone (clone by value) the list A\n","\n","B = A[:]\n","B"]},{"cell_type":"markdown","metadata":{},"source":["Variable **B** references a new copy or clone of the original list. This is demonstrated in the following figure:\n"]},{"cell_type":"markdown","metadata":{},"source":["<img src=\"https://cf-courses-data.s3.us.cloud-object-storage.appdomain.cloud/IBMDeveloperSkillsNetwork-PY0101EN-SkillsNetwork/labs/Module%202/images/ListsVal.gif\" width=\"1000\" />\n"]},{"cell_type":"markdown","metadata":{},"source":["Now if you change <b>A</b>, <b>B</b> will not change:\n"]},{"cell_type":"code","execution_count":null,"metadata":{},"outputs":[],"source":["print('B[0]:', B[0])\n","A[0] = \"hard rock\"\n","print('B[0]:', B[0])"]},{"cell_type":"markdown","metadata":{},"source":["<h2 id=\"quiz\">Quiz on List</h2>\n"]},{"cell_type":"markdown","metadata":{},"source":["Create a list <code>a_list</code>, with the following elements <code>1</code>, <code>hello</code>, <code>\\[1,2,3]</code> and <code>True</code>.\n"]},{"cell_type":"code","execution_count":null,"metadata":{},"outputs":[],"source":["# Write your code below and press Shift+Enter to execute\n"]},{"cell_type":"markdown","metadata":{},"source":["<details><summary>Click here for the solution</summary>\n","\n","```python\n","a_list = [1, 'hello', [1, 2, 3] , True]\n","a_list\n","\n","```\n","\n","</details>\n"]},{"cell_type":"markdown","metadata":{},"source":["Find the value stored at index 1 of <code>a_list</code>.\n"]},{"cell_type":"code","execution_count":null,"metadata":{},"outputs":[],"source":["# Write your code below and press Shift+Enter to execute\n"]},{"cell_type":"markdown","metadata":{},"source":["<details><summary>Click here for the solution</summary>\n","\n","```python\n","a_list[1]\n","\n","```\n","\n","</details>\n"]},{"cell_type":"markdown","metadata":{},"source":["Retrieve the elements stored at index 1, 2 and 3 of <code>a_list</code>.\n"]},{"cell_type":"code","execution_count":null,"metadata":{},"outputs":[],"source":["# Write your code below and press Shift+Enter to execute\n"]},{"cell_type":"markdown","metadata":{},"source":["<details><summary>Click here for the solution</summary>\n","\n","```python\n","a_list[1:4]\n","\n","```\n","\n","</details>\n"]},{"cell_type":"markdown","metadata":{},"source":["Concatenate the following lists <code>A = \\[1, 'a']</code> and <code>B = \\[2, 1, 'd']</code>:\n"]},{"cell_type":"code","execution_count":null,"metadata":{"collapsed":true},"outputs":[],"source":["# Write your code below and press Shift+Enter to execute\n"]},{"cell_type":"markdown","metadata":{},"source":["<details><summary>Click here for the solution</summary>\n","\n","```python\n","A = [1, 'a'] \n","B = [2, 1, 'd']\n","A + B\n","\n","```\n","\n","</details>\n"]},{"cell_type":"markdown","metadata":{},"source":["<hr>\n","<h2>The last exercise!</h2>\n","<p>Congratulations, you have completed your first lesson and hands-on lab in Python. \n","<hr>\n"]},{"cell_type":"markdown","metadata":{},"source":["## Author\n","\n","<a href=\"https://www.linkedin.com/in/joseph-s-50398b136/?utm_medium=Exinfluencer&utm_source=Exinfluencer&utm_content=000026UJ&utm_term=10006555&utm_id=NA-SkillsNetwork-Channel-SkillsNetworkCoursesIBMDeveloperSkillsNetworkPY0101ENSkillsNetwork19487395-2021-01-01\" target=\"_blank\">Joseph Santarcangelo</a>\n","\n","## Other contributors\n","\n","<a href=\"https://www.linkedin.com/in/jiahui-mavis-zhou-a4537814a?utm_medium=Exinfluencer&utm_source=Exinfluencer&utm_content=000026UJ&utm_term=10006555&utm_id=NA-SkillsNetwork-Channel-SkillsNetworkCoursesIBMDeveloperSkillsNetworkPY0101ENSkillsNetwork19487395-2021-01-01\">Mavis Zhou</a>\n","\n","## Change Log\n","\n","| Date (YYYY-MM-DD) | Version | Changed By | Change Description                 |\n","| ----------------- | ------- | ---------- | ---------------------------------- |\n","| 2022-01-10        | 2.1     | Malika     | Removed the readme for GitShare    |\n","| 2020-08-26        | 2.0     | Lavanya    | Moved lab to course repo in GitLab |\n","|                   |         |            |                                    |\n","|                   |         |            |                                    |\n","\n","## <h3 align=\"center\"> © IBM Corporation 2020. All rights reserved. <h3/>\n"]}],"metadata":{"kernelspec":{"display_name":"Python 3","language":"python","name":"python3"},"language_info":{"codemirror_mode":{"name":"ipython","version":3},"file_extension":".py","mimetype":"text/x-python","name":"python","nbconvert_exporter":"python","pygments_lexer":"ipython3","version":"3.7.6"}},"nbformat":4,"nbformat_minor":2}