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review-introduction.ipynb
{
"cells": [
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<center>\n",
" <img src=\"https://cf-courses-data.s3.us.cloud-object-storage.appdomain.cloud/IBMDeveloperSkillsNetwork-DA0101EN-SkillsNetwork/labs/Module%201/images/IDSNlogo.png\" width=\"300\" alt=\"cognitiveclass.ai logo\" />\n",
"</center>\n",
"\n",
"# Introduction Notebook\n",
"\n",
"Estimated time needed: **10** minutes\n",
"\n",
"## Objectives\n",
"\n",
"After completing this lab you will be able to:\n",
"\n",
"* Acquire data in various ways\n",
"* Obtain insights from data with Pandas library\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<h2>Table of Contents</h2>\n",
"\n",
"<div class=\"alert alert-block alert-info\" style=\"margin-top: 20px\">\n",
"<ol>\n",
" <li><a href=\"#data_acquisition\">Data Acquisition</a>\n",
" <li><a href=\"#basic_insight\">Basic Insight of Dataset</a></li>\n",
"</ol>\n",
"\n",
"</div>\n",
"<hr>\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<h1 id=\"data_acquisition\">Data Acquisition</h1>\n",
"<p>\n",
"There are various formats for a dataset: .csv, .json, .xlsx etc. The dataset can be stored in different places, on your local machine or sometimes online.<br>\n",
"\n",
"In this section, you will learn how to load a dataset into our Jupyter Notebook.<br>\n",
"\n",
"In our case, the Automobile Dataset is an online source, and it is in a CSV (comma separated value) format. Let's use this dataset as an example to practice data reading.\n",
"\n",
"<ul>\n",
" <li>Data source: <a href=\"https://archive.ics.uci.edu/ml/machine-learning-databases/autos/imports-85.data?utm_medium=Exinfluencer&utm_source=Exinfluencer&utm_content=000026UJ&utm_term=10006555&utm_id=NA-SkillsNetwork-Channel-SkillsNetworkCoursesIBMDeveloperSkillsNetworkDA0101ENSkillsNetwork20235326-2021-01-01\" target=\"_blank\">https://archive.ics.uci.edu/ml/machine-learning-databases/autos/imports-85.data</a></li>\n",
" <li>Data type: csv</li>\n",
"</ul>\n",
"The Pandas Library is a useful tool that enables us to read various datasets into a dataframe; our Jupyter notebook platforms have a built-in <b>Pandas Library</b> so that all we need to do is import Pandas without installing.\n",
"</p>\n"
]
},
{
"cell_type": "code",
"execution_count": 1,
"metadata": {},
"outputs": [],
"source": [
"# import pandas library\n",
"import pandas as pd\n",
"import numpy as np"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<h2>Read Data</h2>\n",
"<p>\n",
"We use <code>pandas.read_csv()</code> function to read the csv file. In the brackets, we put the file path along with a quotation mark so that pandas will read the file into a dataframe from that address. The file path can be either an URL or your local file address.<br>\n",
"\n",
"Because the data does not include headers, we can add an argument <code>headers = None</code> inside the <code>read_csv()</code> method so that pandas will not automatically set the first row as a header.<br>\n",
"\n",
"You can also assign the dataset to any variable you create.\n",
"\n",
"</p>\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"This dataset was hosted on IBM Cloud object. Click <a href=\"https://cocl.us/DA101EN_object_storage?utm_medium=Exinfluencer&utm_source=Exinfluencer&utm_content=000026UJ&utm_term=10006555&utm_id=NA-SkillsNetwork-Channel-SkillsNetworkCoursesIBMDeveloperSkillsNetworkDA0101ENSkillsNetwork20235326-2021-01-01\">HERE</a> for free storage.\n"
]
},
{
"cell_type": "code",
"execution_count": 6,
"metadata": {},
"outputs": [],
"source": [
"# Import pandas library\n",
"import pandas as pd\n",
"\n",
"# Read the online file by the URL provides above, and assign it to variable \"df\"\n",
"other_path = \"https://cf-courses-data.s3.us.cloud-object-storage.appdomain.cloud/IBMDeveloperSkillsNetwork-DA0101EN-SkillsNetwork/labs/Data%20files/auto.csv\"\n",
"df = pd.read_csv(other_path, header=None)"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"After reading the dataset, we can use the <code>dataframe.head(n)</code> method to check the top n rows of the dataframe, where n is an integer. Contrary to <code>dataframe.head(n)</code>, <code>dataframe.tail(n)</code> will show you the bottom n rows of the dataframe.\n"
]
},
{
"cell_type": "code",
"execution_count": 7,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"The first 5 rows of the dataframe\n"
]
},
{
"data": {
"text/html": [
"<div>\n",
"<style scoped>\n",
" .dataframe tbody tr th:only-of-type {\n",
" vertical-align: middle;\n",
" }\n",
"\n",
" .dataframe tbody tr th {\n",
" vertical-align: top;\n",
" }\n",
"\n",
" .dataframe thead th {\n",
" text-align: right;\n",
" }\n",
"</style>\n",
"<table border=\"1\" class=\"dataframe\">\n",
" <thead>\n",
" <tr style=\"text-align: right;\">\n",
" <th></th>\n",
" <th>0</th>\n",
" <th>1</th>\n",
" <th>2</th>\n",
" <th>3</th>\n",
" <th>4</th>\n",
" <th>5</th>\n",
" <th>6</th>\n",
" <th>7</th>\n",
" <th>8</th>\n",
" <th>9</th>\n",
" <th>...</th>\n",
" <th>16</th>\n",
" <th>17</th>\n",
" <th>18</th>\n",
" <th>19</th>\n",
" <th>20</th>\n",
" <th>21</th>\n",
" <th>22</th>\n",
" <th>23</th>\n",
" <th>24</th>\n",
" <th>25</th>\n",
" </tr>\n",
" </thead>\n",
" <tbody>\n",
" <tr>\n",
" <th>0</th>\n",
" <td>3</td>\n",
" <td>?</td>\n",
" <td>alfa-romero</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>two</td>\n",
" <td>convertible</td>\n",
" <td>rwd</td>\n",
" <td>front</td>\n",
" <td>88.6</td>\n",
" <td>...</td>\n",
" <td>130</td>\n",
" <td>mpfi</td>\n",
" <td>3.47</td>\n",
" <td>2.68</td>\n",
" <td>9.0</td>\n",
" <td>111</td>\n",
" <td>5000</td>\n",
" <td>21</td>\n",
" <td>27</td>\n",
" <td>13495</td>\n",
" </tr>\n",
" <tr>\n",
" <th>1</th>\n",
" <td>3</td>\n",
" <td>?</td>\n",
" <td>alfa-romero</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>two</td>\n",
" <td>convertible</td>\n",
" <td>rwd</td>\n",
" <td>front</td>\n",
" <td>88.6</td>\n",
" <td>...</td>\n",
" <td>130</td>\n",
" <td>mpfi</td>\n",
" <td>3.47</td>\n",
" <td>2.68</td>\n",
" <td>9.0</td>\n",
" <td>111</td>\n",
" <td>5000</td>\n",
" <td>21</td>\n",
" <td>27</td>\n",
" <td>16500</td>\n",
" </tr>\n",
" <tr>\n",
" <th>2</th>\n",
" <td>1</td>\n",
" <td>?</td>\n",
" <td>alfa-romero</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>two</td>\n",
" <td>hatchback</td>\n",
" <td>rwd</td>\n",
" <td>front</td>\n",
" <td>94.5</td>\n",
" <td>...</td>\n",
" <td>152</td>\n",
" <td>mpfi</td>\n",
" <td>2.68</td>\n",
" <td>3.47</td>\n",
" <td>9.0</td>\n",
" <td>154</td>\n",
" <td>5000</td>\n",
" <td>19</td>\n",
" <td>26</td>\n",
" <td>16500</td>\n",
" </tr>\n",
" <tr>\n",
" <th>3</th>\n",
" <td>2</td>\n",
" <td>164</td>\n",
" <td>audi</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>four</td>\n",
" <td>sedan</td>\n",
" <td>fwd</td>\n",
" <td>front</td>\n",
" <td>99.8</td>\n",
" <td>...</td>\n",
" <td>109</td>\n",
" <td>mpfi</td>\n",
" <td>3.19</td>\n",
" <td>3.40</td>\n",
" <td>10.0</td>\n",
" <td>102</td>\n",
" <td>5500</td>\n",
" <td>24</td>\n",
" <td>30</td>\n",
" <td>13950</td>\n",
" </tr>\n",
" <tr>\n",
" <th>4</th>\n",
" <td>2</td>\n",
" <td>164</td>\n",
" <td>audi</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>four</td>\n",
" <td>sedan</td>\n",
" <td>4wd</td>\n",
" <td>front</td>\n",
" <td>99.4</td>\n",
" <td>...</td>\n",
" <td>136</td>\n",
" <td>mpfi</td>\n",
" <td>3.19</td>\n",
" <td>3.40</td>\n",
" <td>8.0</td>\n",
" <td>115</td>\n",
" <td>5500</td>\n",
" <td>18</td>\n",
" <td>22</td>\n",
" <td>17450</td>\n",
" </tr>\n",
" </tbody>\n",
"</table>\n",
"<p>5 rows × 26 columns</p>\n",
"</div>"
],
"text/plain": [
" 0 1 2 3 4 5 6 7 8 9 ... \\\n",
"0 3 ? alfa-romero gas std two convertible rwd front 88.6 ... \n",
"1 3 ? alfa-romero gas std two convertible rwd front 88.6 ... \n",
"2 1 ? alfa-romero gas std two hatchback rwd front 94.5 ... \n",
"3 2 164 audi gas std four sedan fwd front 99.8 ... \n",
"4 2 164 audi gas std four sedan 4wd front 99.4 ... \n",
"\n",
" 16 17 18 19 20 21 22 23 24 25 \n",
"0 130 mpfi 3.47 2.68 9.0 111 5000 21 27 13495 \n",
"1 130 mpfi 3.47 2.68 9.0 111 5000 21 27 16500 \n",
"2 152 mpfi 2.68 3.47 9.0 154 5000 19 26 16500 \n",
"3 109 mpfi 3.19 3.40 10.0 102 5500 24 30 13950 \n",
"4 136 mpfi 3.19 3.40 8.0 115 5500 18 22 17450 \n",
"\n",
"[5 rows x 26 columns]"
]
},
"execution_count": 7,
"metadata": {},
"output_type": "execute_result"
}
],
"source": [
"# show the first 5 rows using dataframe.head() method\n",
"print(\"The first 5 rows of the dataframe\") \n",
"df.head(5)"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<div class=\"alert alert-danger alertdanger\" style=\"margin-top: 20px\">\n",
"<h1> Question #1: </h1>\n",
"<b>Check the bottom 10 rows of data frame \"df\".</b>\n",
"</div>\n"
]
},
{
"cell_type": "code",
"execution_count": 8,
"metadata": {},
"outputs": [
{
"data": {
"text/html": [
"<div>\n",
"<style scoped>\n",
" .dataframe tbody tr th:only-of-type {\n",
" vertical-align: middle;\n",
" }\n",
"\n",
" .dataframe tbody tr th {\n",
" vertical-align: top;\n",
" }\n",
"\n",
" .dataframe thead th {\n",
" text-align: right;\n",
" }\n",
"</style>\n",
"<table border=\"1\" class=\"dataframe\">\n",
" <thead>\n",
" <tr style=\"text-align: right;\">\n",
" <th></th>\n",
" <th>0</th>\n",
" <th>1</th>\n",
" <th>2</th>\n",
" <th>3</th>\n",
" <th>4</th>\n",
" <th>5</th>\n",
" <th>6</th>\n",
" <th>7</th>\n",
" <th>8</th>\n",
" <th>9</th>\n",
" <th>...</th>\n",
" <th>16</th>\n",
" <th>17</th>\n",
" <th>18</th>\n",
" <th>19</th>\n",
" <th>20</th>\n",
" <th>21</th>\n",
" <th>22</th>\n",
" <th>23</th>\n",
" <th>24</th>\n",
" <th>25</th>\n",
" </tr>\n",
" </thead>\n",
" <tbody>\n",
" <tr>\n",
" <th>195</th>\n",
" <td>-1</td>\n",
" <td>74</td>\n",
" <td>volvo</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>four</td>\n",
" <td>wagon</td>\n",
" <td>rwd</td>\n",
" <td>front</td>\n",
" <td>104.3</td>\n",
" <td>...</td>\n",
" <td>141</td>\n",
" <td>mpfi</td>\n",
" <td>3.78</td>\n",
" <td>3.15</td>\n",
" <td>9.5</td>\n",
" <td>114</td>\n",
" <td>5400</td>\n",
" <td>23</td>\n",
" <td>28</td>\n",
" <td>13415</td>\n",
" </tr>\n",
" <tr>\n",
" <th>196</th>\n",
" <td>-2</td>\n",
" <td>103</td>\n",
" <td>volvo</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>four</td>\n",
" <td>sedan</td>\n",
" <td>rwd</td>\n",
" <td>front</td>\n",
" <td>104.3</td>\n",
" <td>...</td>\n",
" <td>141</td>\n",
" <td>mpfi</td>\n",
" <td>3.78</td>\n",
" <td>3.15</td>\n",
" <td>9.5</td>\n",
" <td>114</td>\n",
" <td>5400</td>\n",
" <td>24</td>\n",
" <td>28</td>\n",
" <td>15985</td>\n",
" </tr>\n",
" <tr>\n",
" <th>197</th>\n",
" <td>-1</td>\n",
" <td>74</td>\n",
" <td>volvo</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>four</td>\n",
" <td>wagon</td>\n",
" <td>rwd</td>\n",
" <td>front</td>\n",
" <td>104.3</td>\n",
" <td>...</td>\n",
" <td>141</td>\n",
" <td>mpfi</td>\n",
" <td>3.78</td>\n",
" <td>3.15</td>\n",
" <td>9.5</td>\n",
" <td>114</td>\n",
" <td>5400</td>\n",
" <td>24</td>\n",
" <td>28</td>\n",
" <td>16515</td>\n",
" </tr>\n",
" <tr>\n",
" <th>198</th>\n",
" <td>-2</td>\n",
" <td>103</td>\n",
" <td>volvo</td>\n",
" <td>gas</td>\n",
" <td>turbo</td>\n",
" <td>four</td>\n",
" <td>sedan</td>\n",
" <td>rwd</td>\n",
" <td>front</td>\n",
" <td>104.3</td>\n",
" <td>...</td>\n",
" <td>130</td>\n",
" <td>mpfi</td>\n",
" <td>3.62</td>\n",
" <td>3.15</td>\n",
" <td>7.5</td>\n",
" <td>162</td>\n",
" <td>5100</td>\n",
" <td>17</td>\n",
" <td>22</td>\n",
" <td>18420</td>\n",
" </tr>\n",
" <tr>\n",
" <th>199</th>\n",
" <td>-1</td>\n",
" <td>74</td>\n",
" <td>volvo</td>\n",
" <td>gas</td>\n",
" <td>turbo</td>\n",
" <td>four</td>\n",
" <td>wagon</td>\n",
" <td>rwd</td>\n",
" <td>front</td>\n",
" <td>104.3</td>\n",
" <td>...</td>\n",
" <td>130</td>\n",
" <td>mpfi</td>\n",
" <td>3.62</td>\n",
" <td>3.15</td>\n",
" <td>7.5</td>\n",
" <td>162</td>\n",
" <td>5100</td>\n",
" <td>17</td>\n",
" <td>22</td>\n",
" <td>18950</td>\n",
" </tr>\n",
" <tr>\n",
" <th>200</th>\n",
" <td>-1</td>\n",
" <td>95</td>\n",
" <td>volvo</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>four</td>\n",
" <td>sedan</td>\n",
" <td>rwd</td>\n",
" <td>front</td>\n",
" <td>109.1</td>\n",
" <td>...</td>\n",
" <td>141</td>\n",
" <td>mpfi</td>\n",
" <td>3.78</td>\n",
" <td>3.15</td>\n",
" <td>9.5</td>\n",
" <td>114</td>\n",
" <td>5400</td>\n",
" <td>23</td>\n",
" <td>28</td>\n",
" <td>16845</td>\n",
" </tr>\n",
" <tr>\n",
" <th>201</th>\n",
" <td>-1</td>\n",
" <td>95</td>\n",
" <td>volvo</td>\n",
" <td>gas</td>\n",
" <td>turbo</td>\n",
" <td>four</td>\n",
" <td>sedan</td>\n",
" <td>rwd</td>\n",
" <td>front</td>\n",
" <td>109.1</td>\n",
" <td>...</td>\n",
" <td>141</td>\n",
" <td>mpfi</td>\n",
" <td>3.78</td>\n",
" <td>3.15</td>\n",
" <td>8.7</td>\n",
" <td>160</td>\n",
" <td>5300</td>\n",
" <td>19</td>\n",
" <td>25</td>\n",
" <td>19045</td>\n",
" </tr>\n",
" <tr>\n",
" <th>202</th>\n",
" <td>-1</td>\n",
" <td>95</td>\n",
" <td>volvo</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>four</td>\n",
" <td>sedan</td>\n",
" <td>rwd</td>\n",
" <td>front</td>\n",
" <td>109.1</td>\n",
" <td>...</td>\n",
" <td>173</td>\n",
" <td>mpfi</td>\n",
" <td>3.58</td>\n",
" <td>2.87</td>\n",
" <td>8.8</td>\n",
" <td>134</td>\n",
" <td>5500</td>\n",
" <td>18</td>\n",
" <td>23</td>\n",
" <td>21485</td>\n",
" </tr>\n",
" <tr>\n",
" <th>203</th>\n",
" <td>-1</td>\n",
" <td>95</td>\n",
" <td>volvo</td>\n",
" <td>diesel</td>\n",
" <td>turbo</td>\n",
" <td>four</td>\n",
" <td>sedan</td>\n",
" <td>rwd</td>\n",
" <td>front</td>\n",
" <td>109.1</td>\n",
" <td>...</td>\n",
" <td>145</td>\n",
" <td>idi</td>\n",
" <td>3.01</td>\n",
" <td>3.40</td>\n",
" <td>23.0</td>\n",
" <td>106</td>\n",
" <td>4800</td>\n",
" <td>26</td>\n",
" <td>27</td>\n",
" <td>22470</td>\n",
" </tr>\n",
" <tr>\n",
" <th>204</th>\n",
" <td>-1</td>\n",
" <td>95</td>\n",
" <td>volvo</td>\n",
" <td>gas</td>\n",
" <td>turbo</td>\n",
" <td>four</td>\n",
" <td>sedan</td>\n",
" <td>rwd</td>\n",
" <td>front</td>\n",
" <td>109.1</td>\n",
" <td>...</td>\n",
" <td>141</td>\n",
" <td>mpfi</td>\n",
" <td>3.78</td>\n",
" <td>3.15</td>\n",
" <td>9.5</td>\n",
" <td>114</td>\n",
" <td>5400</td>\n",
" <td>19</td>\n",
" <td>25</td>\n",
" <td>22625</td>\n",
" </tr>\n",
" </tbody>\n",
"</table>\n",
"<p>10 rows × 26 columns</p>\n",
"</div>"
],
"text/plain": [
" 0 1 2 3 4 5 6 7 8 9 ... 16 \\\n",
"195 -1 74 volvo gas std four wagon rwd front 104.3 ... 141 \n",
"196 -2 103 volvo gas std four sedan rwd front 104.3 ... 141 \n",
"197 -1 74 volvo gas std four wagon rwd front 104.3 ... 141 \n",
"198 -2 103 volvo gas turbo four sedan rwd front 104.3 ... 130 \n",
"199 -1 74 volvo gas turbo four wagon rwd front 104.3 ... 130 \n",
"200 -1 95 volvo gas std four sedan rwd front 109.1 ... 141 \n",
"201 -1 95 volvo gas turbo four sedan rwd front 109.1 ... 141 \n",
"202 -1 95 volvo gas std four sedan rwd front 109.1 ... 173 \n",
"203 -1 95 volvo diesel turbo four sedan rwd front 109.1 ... 145 \n",
"204 -1 95 volvo gas turbo four sedan rwd front 109.1 ... 141 \n",
"\n",
" 17 18 19 20 21 22 23 24 25 \n",
"195 mpfi 3.78 3.15 9.5 114 5400 23 28 13415 \n",
"196 mpfi 3.78 3.15 9.5 114 5400 24 28 15985 \n",
"197 mpfi 3.78 3.15 9.5 114 5400 24 28 16515 \n",
"198 mpfi 3.62 3.15 7.5 162 5100 17 22 18420 \n",
"199 mpfi 3.62 3.15 7.5 162 5100 17 22 18950 \n",
"200 mpfi 3.78 3.15 9.5 114 5400 23 28 16845 \n",
"201 mpfi 3.78 3.15 8.7 160 5300 19 25 19045 \n",
"202 mpfi 3.58 2.87 8.8 134 5500 18 23 21485 \n",
"203 idi 3.01 3.40 23.0 106 4800 26 27 22470 \n",
"204 mpfi 3.78 3.15 9.5 114 5400 19 25 22625 \n",
"\n",
"[10 rows x 26 columns]"
]
},
"execution_count": 8,
"metadata": {},
"output_type": "execute_result"
}
],
"source": [
"# Write your code below and press Shift+Enter to execute \n",
"df.tail(10)"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<details><summary>Click here for the solution</summary>\n",
"\n",
"```python\n",
"print(\"The last 10 rows of the dataframe\\n\")\n",
"df.tail(10)\n",
"```\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<h3>Add Headers</h3>\n",
"<p>\n",
"Take a look at our dataset. Pandas automatically set the header with an integer starting from 0.\n",
"</p>\n",
"<p>\n",
"To better describe our data, we can introduce a header. This information is available at: <a href=\"https://archive.ics.uci.edu/ml/datasets/Automobile?utm_medium=Exinfluencer&utm_source=Exinfluencer&utm_content=000026UJ&utm_term=10006555&utm_id=NA-SkillsNetwork-Channel-SkillsNetworkCoursesIBMDeveloperSkillsNetworkDA0101ENSkillsNetwork20235326-2021-01-01\" target=\"_blank\">https://archive.ics.uci.edu/ml/datasets/Automobile</a>.\n",
"</p>\n",
"<p>\n",
"Thus, we have to add headers manually.\n",
"</p>\n",
"<p>\n",
"First, we create a list \"headers\" that include all column names in order.\n",
"Then, we use <code>dataframe.columns = headers</code> to replace the headers with the list we created.\n",
"</p>\n"
]
},
{
"cell_type": "code",
"execution_count": 15,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"headers\n",
" ['symboling', 'normalized-losses', 'make', 'fuel-type', 'aspiration', 'num-of-doors', 'body-style', 'drive-wheels', 'engine-location', 'wheel-base', 'length', 'width', 'height', 'curb-weight', 'engine-type', 'num-of-cylinders', 'engine-size', 'fuel-system', 'bore', 'stroke', 'compression-ratio', 'horsepower', 'peak-rpm', 'city-mpg', 'highway-mpg', 'price']\n"
]
}
],
"source": [
"# create headers list\n",
"headers = [\"symboling\",\"normalized-losses\",\"make\",\"fuel-type\",\"aspiration\", \"num-of-doors\",\"body-style\",\n",
" \"drive-wheels\",\"engine-location\",\"wheel-base\", \"length\",\"width\",\"height\",\"curb-weight\",\"engine-type\",\n",
" \"num-of-cylinders\", \"engine-size\",\"fuel-system\",\"bore\",\"stroke\",\"compression-ratio\",\"horsepower\",\n",
" \"peak-rpm\",\"city-mpg\",\"highway-mpg\",\"price\"]\n",
"print(\"headers\\n\", headers)"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"We replace headers and recheck our dataframe:\n"
]
},
{
"cell_type": "code",
"execution_count": 16,
"metadata": {},
"outputs": [
{
"data": {
"text/html": [
"<div>\n",
"<style scoped>\n",
" .dataframe tbody tr th:only-of-type {\n",
" vertical-align: middle;\n",
" }\n",
"\n",
" .dataframe tbody tr th {\n",
" vertical-align: top;\n",
" }\n",
"\n",
" .dataframe thead th {\n",
" text-align: right;\n",
" }\n",
"</style>\n",
"<table border=\"1\" class=\"dataframe\">\n",
" <thead>\n",
" <tr style=\"text-align: right;\">\n",
" <th></th>\n",
" <th>symboling</th>\n",
" <th>normalized-losses</th>\n",
" <th>make</th>\n",
" <th>fuel-type</th>\n",
" <th>aspiration</th>\n",
" <th>num-of-doors</th>\n",
" <th>body-style</th>\n",
" <th>drive-wheels</th>\n",
" <th>engine-location</th>\n",
" <th>wheel-base</th>\n",
" <th>...</th>\n",
" <th>engine-size</th>\n",
" <th>fuel-system</th>\n",
" <th>bore</th>\n",
" <th>stroke</th>\n",
" <th>compression-ratio</th>\n",
" <th>horsepower</th>\n",
" <th>peak-rpm</th>\n",
" <th>city-mpg</th>\n",
" <th>highway-mpg</th>\n",
" <th>price</th>\n",
" </tr>\n",
" </thead>\n",
" <tbody>\n",
" <tr>\n",
" <th>0</th>\n",
" <td>3</td>\n",
" <td>?</td>\n",
" <td>alfa-romero</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>two</td>\n",
" <td>convertible</td>\n",
" <td>rwd</td>\n",
" <td>front</td>\n",
" <td>88.6</td>\n",
" <td>...</td>\n",
" <td>130</td>\n",
" <td>mpfi</td>\n",
" <td>3.47</td>\n",
" <td>2.68</td>\n",
" <td>9.0</td>\n",
" <td>111</td>\n",
" <td>5000</td>\n",
" <td>21</td>\n",
" <td>27</td>\n",
" <td>13495</td>\n",
" </tr>\n",
" <tr>\n",
" <th>1</th>\n",
" <td>3</td>\n",
" <td>?</td>\n",
" <td>alfa-romero</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>two</td>\n",
" <td>convertible</td>\n",
" <td>rwd</td>\n",
" <td>front</td>\n",
" <td>88.6</td>\n",
" <td>...</td>\n",
" <td>130</td>\n",
" <td>mpfi</td>\n",
" <td>3.47</td>\n",
" <td>2.68</td>\n",
" <td>9.0</td>\n",
" <td>111</td>\n",
" <td>5000</td>\n",
" <td>21</td>\n",
" <td>27</td>\n",
" <td>16500</td>\n",
" </tr>\n",
" <tr>\n",
" <th>2</th>\n",
" <td>1</td>\n",
" <td>?</td>\n",
" <td>alfa-romero</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>two</td>\n",
" <td>hatchback</td>\n",
" <td>rwd</td>\n",
" <td>front</td>\n",
" <td>94.5</td>\n",
" <td>...</td>\n",
" <td>152</td>\n",
" <td>mpfi</td>\n",
" <td>2.68</td>\n",
" <td>3.47</td>\n",
" <td>9.0</td>\n",
" <td>154</td>\n",
" <td>5000</td>\n",
" <td>19</td>\n",
" <td>26</td>\n",
" <td>16500</td>\n",
" </tr>\n",
" <tr>\n",
" <th>3</th>\n",
" <td>2</td>\n",
" <td>164</td>\n",
" <td>audi</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>four</td>\n",
" <td>sedan</td>\n",
" <td>fwd</td>\n",
" <td>front</td>\n",
" <td>99.8</td>\n",
" <td>...</td>\n",
" <td>109</td>\n",
" <td>mpfi</td>\n",
" <td>3.19</td>\n",
" <td>3.40</td>\n",
" <td>10.0</td>\n",
" <td>102</td>\n",
" <td>5500</td>\n",
" <td>24</td>\n",
" <td>30</td>\n",
" <td>13950</td>\n",
" </tr>\n",
" <tr>\n",
" <th>4</th>\n",
" <td>2</td>\n",
" <td>164</td>\n",
" <td>audi</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>four</td>\n",
" <td>sedan</td>\n",
" <td>4wd</td>\n",
" <td>front</td>\n",
" <td>99.4</td>\n",
" <td>...</td>\n",
" <td>136</td>\n",
" <td>mpfi</td>\n",
" <td>3.19</td>\n",
" <td>3.40</td>\n",
" <td>8.0</td>\n",
" <td>115</td>\n",
" <td>5500</td>\n",
" <td>18</td>\n",
" <td>22</td>\n",
" <td>17450</td>\n",
" </tr>\n",
" <tr>\n",
" <th>5</th>\n",
" <td>2</td>\n",
" <td>?</td>\n",
" <td>audi</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>two</td>\n",
" <td>sedan</td>\n",
" <td>fwd</td>\n",
" <td>front</td>\n",
" <td>99.8</td>\n",
" <td>...</td>\n",
" <td>136</td>\n",
" <td>mpfi</td>\n",
" <td>3.19</td>\n",
" <td>3.40</td>\n",
" <td>8.5</td>\n",
" <td>110</td>\n",
" <td>5500</td>\n",
" <td>19</td>\n",
" <td>25</td>\n",
" <td>15250</td>\n",
" </tr>\n",
" <tr>\n",
" <th>6</th>\n",
" <td>1</td>\n",
" <td>158</td>\n",
" <td>audi</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>four</td>\n",
" <td>sedan</td>\n",
" <td>fwd</td>\n",
" <td>front</td>\n",
" <td>105.8</td>\n",
" <td>...</td>\n",
" <td>136</td>\n",
" <td>mpfi</td>\n",
" <td>3.19</td>\n",
" <td>3.40</td>\n",
" <td>8.5</td>\n",
" <td>110</td>\n",
" <td>5500</td>\n",
" <td>19</td>\n",
" <td>25</td>\n",
" <td>17710</td>\n",
" </tr>\n",
" <tr>\n",
" <th>7</th>\n",
" <td>1</td>\n",
" <td>?</td>\n",
" <td>audi</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>four</td>\n",
" <td>wagon</td>\n",
" <td>fwd</td>\n",
" <td>front</td>\n",
" <td>105.8</td>\n",
" <td>...</td>\n",
" <td>136</td>\n",
" <td>mpfi</td>\n",
" <td>3.19</td>\n",
" <td>3.40</td>\n",
" <td>8.5</td>\n",
" <td>110</td>\n",
" <td>5500</td>\n",
" <td>19</td>\n",
" <td>25</td>\n",
" <td>18920</td>\n",
" </tr>\n",
" <tr>\n",
" <th>8</th>\n",
" <td>1</td>\n",
" <td>158</td>\n",
" <td>audi</td>\n",
" <td>gas</td>\n",
" <td>turbo</td>\n",
" <td>four</td>\n",
" <td>sedan</td>\n",
" <td>fwd</td>\n",
" <td>front</td>\n",
" <td>105.8</td>\n",
" <td>...</td>\n",
" <td>131</td>\n",
" <td>mpfi</td>\n",
" <td>3.13</td>\n",
" <td>3.40</td>\n",
" <td>8.3</td>\n",
" <td>140</td>\n",
" <td>5500</td>\n",
" <td>17</td>\n",
" <td>20</td>\n",
" <td>23875</td>\n",
" </tr>\n",
" <tr>\n",
" <th>9</th>\n",
" <td>0</td>\n",
" <td>?</td>\n",
" <td>audi</td>\n",
" <td>gas</td>\n",
" <td>turbo</td>\n",
" <td>two</td>\n",
" <td>hatchback</td>\n",
" <td>4wd</td>\n",
" <td>front</td>\n",
" <td>99.5</td>\n",
" <td>...</td>\n",
" <td>131</td>\n",
" <td>mpfi</td>\n",
" <td>3.13</td>\n",
" <td>3.40</td>\n",
" <td>7.0</td>\n",
" <td>160</td>\n",
" <td>5500</td>\n",
" <td>16</td>\n",
" <td>22</td>\n",
" <td>?</td>\n",
" </tr>\n",
" </tbody>\n",
"</table>\n",
"<p>10 rows × 26 columns</p>\n",
"</div>"
],
"text/plain": [
" symboling normalized-losses make fuel-type aspiration num-of-doors \\\n",
"0 3 ? alfa-romero gas std two \n",
"1 3 ? alfa-romero gas std two \n",
"2 1 ? alfa-romero gas std two \n",
"3 2 164 audi gas std four \n",
"4 2 164 audi gas std four \n",
"5 2 ? audi gas std two \n",
"6 1 158 audi gas std four \n",
"7 1 ? audi gas std four \n",
"8 1 158 audi gas turbo four \n",
"9 0 ? audi gas turbo two \n",
"\n",
" body-style drive-wheels engine-location wheel-base ... engine-size \\\n",
"0 convertible rwd front 88.6 ... 130 \n",
"1 convertible rwd front 88.6 ... 130 \n",
"2 hatchback rwd front 94.5 ... 152 \n",
"3 sedan fwd front 99.8 ... 109 \n",
"4 sedan 4wd front 99.4 ... 136 \n",
"5 sedan fwd front 99.8 ... 136 \n",
"6 sedan fwd front 105.8 ... 136 \n",
"7 wagon fwd front 105.8 ... 136 \n",
"8 sedan fwd front 105.8 ... 131 \n",
"9 hatchback 4wd front 99.5 ... 131 \n",
"\n",
" fuel-system bore stroke compression-ratio horsepower peak-rpm city-mpg \\\n",
"0 mpfi 3.47 2.68 9.0 111 5000 21 \n",
"1 mpfi 3.47 2.68 9.0 111 5000 21 \n",
"2 mpfi 2.68 3.47 9.0 154 5000 19 \n",
"3 mpfi 3.19 3.40 10.0 102 5500 24 \n",
"4 mpfi 3.19 3.40 8.0 115 5500 18 \n",
"5 mpfi 3.19 3.40 8.5 110 5500 19 \n",
"6 mpfi 3.19 3.40 8.5 110 5500 19 \n",
"7 mpfi 3.19 3.40 8.5 110 5500 19 \n",
"8 mpfi 3.13 3.40 8.3 140 5500 17 \n",
"9 mpfi 3.13 3.40 7.0 160 5500 16 \n",
"\n",
" highway-mpg price \n",
"0 27 13495 \n",
"1 27 16500 \n",
"2 26 16500 \n",
"3 30 13950 \n",
"4 22 17450 \n",
"5 25 15250 \n",
"6 25 17710 \n",
"7 25 18920 \n",
"8 20 23875 \n",
"9 22 ? \n",
"\n",
"[10 rows x 26 columns]"
]
},
"execution_count": 16,
"metadata": {},
"output_type": "execute_result"
}
],
"source": [
"df.columns = headers\n",
"df.head(10)"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"We need to replace the \"?\" symbol with NaN so the dropna() can remove the missing values:\n"
]
},
{
"cell_type": "code",
"execution_count": 18,
"metadata": {},
"outputs": [],
"source": [
"df1=df.replace('?',np.NaN)\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"We can drop missing values along the column \"price\" as follows:\n"
]
},
{
"cell_type": "code",
"execution_count": 19,
"metadata": {},
"outputs": [
{
"data": {
"text/html": [
"<div>\n",
"<style scoped>\n",
" .dataframe tbody tr th:only-of-type {\n",
" vertical-align: middle;\n",
" }\n",
"\n",
" .dataframe tbody tr th {\n",
" vertical-align: top;\n",
" }\n",
"\n",
" .dataframe thead th {\n",
" text-align: right;\n",
" }\n",
"</style>\n",
"<table border=\"1\" class=\"dataframe\">\n",
" <thead>\n",
" <tr style=\"text-align: right;\">\n",
" <th></th>\n",
" <th>symboling</th>\n",
" <th>normalized-losses</th>\n",
" <th>make</th>\n",
" <th>fuel-type</th>\n",
" <th>aspiration</th>\n",
" <th>num-of-doors</th>\n",
" <th>body-style</th>\n",
" <th>drive-wheels</th>\n",
" <th>engine-location</th>\n",
" <th>wheel-base</th>\n",
" <th>...</th>\n",
" <th>engine-size</th>\n",
" <th>fuel-system</th>\n",
" <th>bore</th>\n",
" <th>stroke</th>\n",
" <th>compression-ratio</th>\n",
" <th>horsepower</th>\n",
" <th>peak-rpm</th>\n",
" <th>city-mpg</th>\n",
" <th>highway-mpg</th>\n",
" <th>price</th>\n",
" </tr>\n",
" </thead>\n",
" <tbody>\n",
" <tr>\n",
" <th>0</th>\n",
" <td>3</td>\n",
" <td>NaN</td>\n",
" <td>alfa-romero</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>two</td>\n",
" <td>convertible</td>\n",
" <td>rwd</td>\n",
" <td>front</td>\n",
" <td>88.6</td>\n",
" <td>...</td>\n",
" <td>130</td>\n",
" <td>mpfi</td>\n",
" <td>3.47</td>\n",
" <td>2.68</td>\n",
" <td>9.0</td>\n",
" <td>111</td>\n",
" <td>5000</td>\n",
" <td>21</td>\n",
" <td>27</td>\n",
" <td>13495</td>\n",
" </tr>\n",
" <tr>\n",
" <th>1</th>\n",
" <td>3</td>\n",
" <td>NaN</td>\n",
" <td>alfa-romero</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>two</td>\n",
" <td>convertible</td>\n",
" <td>rwd</td>\n",
" <td>front</td>\n",
" <td>88.6</td>\n",
" <td>...</td>\n",
" <td>130</td>\n",
" <td>mpfi</td>\n",
" <td>3.47</td>\n",
" <td>2.68</td>\n",
" <td>9.0</td>\n",
" <td>111</td>\n",
" <td>5000</td>\n",
" <td>21</td>\n",
" <td>27</td>\n",
" <td>16500</td>\n",
" </tr>\n",
" <tr>\n",
" <th>2</th>\n",
" <td>1</td>\n",
" <td>NaN</td>\n",
" <td>alfa-romero</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>two</td>\n",
" <td>hatchback</td>\n",
" <td>rwd</td>\n",
" <td>front</td>\n",
" <td>94.5</td>\n",
" <td>...</td>\n",
" <td>152</td>\n",
" <td>mpfi</td>\n",
" <td>2.68</td>\n",
" <td>3.47</td>\n",
" <td>9.0</td>\n",
" <td>154</td>\n",
" <td>5000</td>\n",
" <td>19</td>\n",
" <td>26</td>\n",
" <td>16500</td>\n",
" </tr>\n",
" <tr>\n",
" <th>3</th>\n",
" <td>2</td>\n",
" <td>164</td>\n",
" <td>audi</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>four</td>\n",
" <td>sedan</td>\n",
" <td>fwd</td>\n",
" <td>front</td>\n",
" <td>99.8</td>\n",
" <td>...</td>\n",
" <td>109</td>\n",
" <td>mpfi</td>\n",
" <td>3.19</td>\n",
" <td>3.40</td>\n",
" <td>10.0</td>\n",
" <td>102</td>\n",
" <td>5500</td>\n",
" <td>24</td>\n",
" <td>30</td>\n",
" <td>13950</td>\n",
" </tr>\n",
" <tr>\n",
" <th>4</th>\n",
" <td>2</td>\n",
" <td>164</td>\n",
" <td>audi</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>four</td>\n",
" <td>sedan</td>\n",
" <td>4wd</td>\n",
" <td>front</td>\n",
" <td>99.4</td>\n",
" <td>...</td>\n",
" <td>136</td>\n",
" <td>mpfi</td>\n",
" <td>3.19</td>\n",
" <td>3.40</td>\n",
" <td>8.0</td>\n",
" <td>115</td>\n",
" <td>5500</td>\n",
" <td>18</td>\n",
" <td>22</td>\n",
" <td>17450</td>\n",
" </tr>\n",
" <tr>\n",
" <th>5</th>\n",
" <td>2</td>\n",
" <td>NaN</td>\n",
" <td>audi</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>two</td>\n",
" <td>sedan</td>\n",
" <td>fwd</td>\n",
" <td>front</td>\n",
" <td>99.8</td>\n",
" <td>...</td>\n",
" <td>136</td>\n",
" <td>mpfi</td>\n",
" <td>3.19</td>\n",
" <td>3.40</td>\n",
" <td>8.5</td>\n",
" <td>110</td>\n",
" <td>5500</td>\n",
" <td>19</td>\n",
" <td>25</td>\n",
" <td>15250</td>\n",
" </tr>\n",
" <tr>\n",
" <th>6</th>\n",
" <td>1</td>\n",
" <td>158</td>\n",
" <td>audi</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>four</td>\n",
" <td>sedan</td>\n",
" <td>fwd</td>\n",
" <td>front</td>\n",
" <td>105.8</td>\n",
" <td>...</td>\n",
" <td>136</td>\n",
" <td>mpfi</td>\n",
" <td>3.19</td>\n",
" <td>3.40</td>\n",
" <td>8.5</td>\n",
" <td>110</td>\n",
" <td>5500</td>\n",
" <td>19</td>\n",
" <td>25</td>\n",
" <td>17710</td>\n",
" </tr>\n",
" <tr>\n",
" <th>7</th>\n",
" <td>1</td>\n",
" <td>NaN</td>\n",
" <td>audi</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>four</td>\n",
" <td>wagon</td>\n",
" <td>fwd</td>\n",
" <td>front</td>\n",
" <td>105.8</td>\n",
" <td>...</td>\n",
" <td>136</td>\n",
" <td>mpfi</td>\n",
" <td>3.19</td>\n",
" <td>3.40</td>\n",
" <td>8.5</td>\n",
" <td>110</td>\n",
" <td>5500</td>\n",
" <td>19</td>\n",
" <td>25</td>\n",
" <td>18920</td>\n",
" </tr>\n",
" <tr>\n",
" <th>8</th>\n",
" <td>1</td>\n",
" <td>158</td>\n",
" <td>audi</td>\n",
" <td>gas</td>\n",
" <td>turbo</td>\n",
" <td>four</td>\n",
" <td>sedan</td>\n",
" <td>fwd</td>\n",
" <td>front</td>\n",
" <td>105.8</td>\n",
" <td>...</td>\n",
" <td>131</td>\n",
" <td>mpfi</td>\n",
" <td>3.13</td>\n",
" <td>3.40</td>\n",
" <td>8.3</td>\n",
" <td>140</td>\n",
" <td>5500</td>\n",
" <td>17</td>\n",
" <td>20</td>\n",
" <td>23875</td>\n",
" </tr>\n",
" <tr>\n",
" <th>10</th>\n",
" <td>2</td>\n",
" <td>192</td>\n",
" <td>bmw</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>two</td>\n",
" <td>sedan</td>\n",
" <td>rwd</td>\n",
" <td>front</td>\n",
" <td>101.2</td>\n",
" <td>...</td>\n",
" <td>108</td>\n",
" <td>mpfi</td>\n",
" <td>3.50</td>\n",
" <td>2.80</td>\n",
" <td>8.8</td>\n",
" <td>101</td>\n",
" <td>5800</td>\n",
" <td>23</td>\n",
" <td>29</td>\n",
" <td>16430</td>\n",
" </tr>\n",
" <tr>\n",
" <th>11</th>\n",
" <td>0</td>\n",
" <td>192</td>\n",
" <td>bmw</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>four</td>\n",
" <td>sedan</td>\n",
" <td>rwd</td>\n",
" <td>front</td>\n",
" <td>101.2</td>\n",
" <td>...</td>\n",
" <td>108</td>\n",
" <td>mpfi</td>\n",
" <td>3.50</td>\n",
" <td>2.80</td>\n",
" <td>8.8</td>\n",
" <td>101</td>\n",
" <td>5800</td>\n",
" <td>23</td>\n",
" <td>29</td>\n",
" <td>16925</td>\n",
" </tr>\n",
" <tr>\n",
" <th>12</th>\n",
" <td>0</td>\n",
" <td>188</td>\n",
" <td>bmw</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>two</td>\n",
" <td>sedan</td>\n",
" <td>rwd</td>\n",
" <td>front</td>\n",
" <td>101.2</td>\n",
" <td>...</td>\n",
" <td>164</td>\n",
" <td>mpfi</td>\n",
" <td>3.31</td>\n",
" <td>3.19</td>\n",
" <td>9.0</td>\n",
" <td>121</td>\n",
" <td>4250</td>\n",
" <td>21</td>\n",
" <td>28</td>\n",
" <td>20970</td>\n",
" </tr>\n",
" <tr>\n",
" <th>13</th>\n",
" <td>0</td>\n",
" <td>188</td>\n",
" <td>bmw</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>four</td>\n",
" <td>sedan</td>\n",
" <td>rwd</td>\n",
" <td>front</td>\n",
" <td>101.2</td>\n",
" <td>...</td>\n",
" <td>164</td>\n",
" <td>mpfi</td>\n",
" <td>3.31</td>\n",
" <td>3.19</td>\n",
" <td>9.0</td>\n",
" <td>121</td>\n",
" <td>4250</td>\n",
" <td>21</td>\n",
" <td>28</td>\n",
" <td>21105</td>\n",
" </tr>\n",
" <tr>\n",
" <th>14</th>\n",
" <td>1</td>\n",
" <td>NaN</td>\n",
" <td>bmw</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>four</td>\n",
" <td>sedan</td>\n",
" <td>rwd</td>\n",
" <td>front</td>\n",
" <td>103.5</td>\n",
" <td>...</td>\n",
" <td>164</td>\n",
" <td>mpfi</td>\n",
" <td>3.31</td>\n",
" <td>3.19</td>\n",
" <td>9.0</td>\n",
" <td>121</td>\n",
" <td>4250</td>\n",
" <td>20</td>\n",
" <td>25</td>\n",
" <td>24565</td>\n",
" </tr>\n",
" <tr>\n",
" <th>15</th>\n",
" <td>0</td>\n",
" <td>NaN</td>\n",
" <td>bmw</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>four</td>\n",
" <td>sedan</td>\n",
" <td>rwd</td>\n",
" <td>front</td>\n",
" <td>103.5</td>\n",
" <td>...</td>\n",
" <td>209</td>\n",
" <td>mpfi</td>\n",
" <td>3.62</td>\n",
" <td>3.39</td>\n",
" <td>8.0</td>\n",
" <td>182</td>\n",
" <td>5400</td>\n",
" <td>16</td>\n",
" <td>22</td>\n",
" <td>30760</td>\n",
" </tr>\n",
" <tr>\n",
" <th>16</th>\n",
" <td>0</td>\n",
" <td>NaN</td>\n",
" <td>bmw</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>two</td>\n",
" <td>sedan</td>\n",
" <td>rwd</td>\n",
" <td>front</td>\n",
" <td>103.5</td>\n",
" <td>...</td>\n",
" <td>209</td>\n",
" <td>mpfi</td>\n",
" <td>3.62</td>\n",
" <td>3.39</td>\n",
" <td>8.0</td>\n",
" <td>182</td>\n",
" <td>5400</td>\n",
" <td>16</td>\n",
" <td>22</td>\n",
" <td>41315</td>\n",
" </tr>\n",
" <tr>\n",
" <th>17</th>\n",
" <td>0</td>\n",
" <td>NaN</td>\n",
" <td>bmw</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>four</td>\n",
" <td>sedan</td>\n",
" <td>rwd</td>\n",
" <td>front</td>\n",
" <td>110.0</td>\n",
" <td>...</td>\n",
" <td>209</td>\n",
" <td>mpfi</td>\n",
" <td>3.62</td>\n",
" <td>3.39</td>\n",
" <td>8.0</td>\n",
" <td>182</td>\n",
" <td>5400</td>\n",
" <td>15</td>\n",
" <td>20</td>\n",
" <td>36880</td>\n",
" </tr>\n",
" <tr>\n",
" <th>18</th>\n",
" <td>2</td>\n",
" <td>121</td>\n",
" <td>chevrolet</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>two</td>\n",
" <td>hatchback</td>\n",
" <td>fwd</td>\n",
" <td>front</td>\n",
" <td>88.4</td>\n",
" <td>...</td>\n",
" <td>61</td>\n",
" <td>2bbl</td>\n",
" <td>2.91</td>\n",
" <td>3.03</td>\n",
" <td>9.5</td>\n",
" <td>48</td>\n",
" <td>5100</td>\n",
" <td>47</td>\n",
" <td>53</td>\n",
" <td>5151</td>\n",
" </tr>\n",
" <tr>\n",
" <th>19</th>\n",
" <td>1</td>\n",
" <td>98</td>\n",
" <td>chevrolet</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>two</td>\n",
" <td>hatchback</td>\n",
" <td>fwd</td>\n",
" <td>front</td>\n",
" <td>94.5</td>\n",
" <td>...</td>\n",
" <td>90</td>\n",
" <td>2bbl</td>\n",
" <td>3.03</td>\n",
" <td>3.11</td>\n",
" <td>9.6</td>\n",
" <td>70</td>\n",
" <td>5400</td>\n",
" <td>38</td>\n",
" <td>43</td>\n",
" <td>6295</td>\n",
" </tr>\n",
" <tr>\n",
" <th>20</th>\n",
" <td>0</td>\n",
" <td>81</td>\n",
" <td>chevrolet</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>four</td>\n",
" <td>sedan</td>\n",
" <td>fwd</td>\n",
" <td>front</td>\n",
" <td>94.5</td>\n",
" <td>...</td>\n",
" <td>90</td>\n",
" <td>2bbl</td>\n",
" <td>3.03</td>\n",
" <td>3.11</td>\n",
" <td>9.6</td>\n",
" <td>70</td>\n",
" <td>5400</td>\n",
" <td>38</td>\n",
" <td>43</td>\n",
" <td>6575</td>\n",
" </tr>\n",
" </tbody>\n",
"</table>\n",
"<p>20 rows × 26 columns</p>\n",
"</div>"
],
"text/plain": [
" symboling normalized-losses make fuel-type aspiration \\\n",
"0 3 NaN alfa-romero gas std \n",
"1 3 NaN alfa-romero gas std \n",
"2 1 NaN alfa-romero gas std \n",
"3 2 164 audi gas std \n",
"4 2 164 audi gas std \n",
"5 2 NaN audi gas std \n",
"6 1 158 audi gas std \n",
"7 1 NaN audi gas std \n",
"8 1 158 audi gas turbo \n",
"10 2 192 bmw gas std \n",
"11 0 192 bmw gas std \n",
"12 0 188 bmw gas std \n",
"13 0 188 bmw gas std \n",
"14 1 NaN bmw gas std \n",
"15 0 NaN bmw gas std \n",
"16 0 NaN bmw gas std \n",
"17 0 NaN bmw gas std \n",
"18 2 121 chevrolet gas std \n",
"19 1 98 chevrolet gas std \n",
"20 0 81 chevrolet gas std \n",
"\n",
" num-of-doors body-style drive-wheels engine-location wheel-base ... \\\n",
"0 two convertible rwd front 88.6 ... \n",
"1 two convertible rwd front 88.6 ... \n",
"2 two hatchback rwd front 94.5 ... \n",
"3 four sedan fwd front 99.8 ... \n",
"4 four sedan 4wd front 99.4 ... \n",
"5 two sedan fwd front 99.8 ... \n",
"6 four sedan fwd front 105.8 ... \n",
"7 four wagon fwd front 105.8 ... \n",
"8 four sedan fwd front 105.8 ... \n",
"10 two sedan rwd front 101.2 ... \n",
"11 four sedan rwd front 101.2 ... \n",
"12 two sedan rwd front 101.2 ... \n",
"13 four sedan rwd front 101.2 ... \n",
"14 four sedan rwd front 103.5 ... \n",
"15 four sedan rwd front 103.5 ... \n",
"16 two sedan rwd front 103.5 ... \n",
"17 four sedan rwd front 110.0 ... \n",
"18 two hatchback fwd front 88.4 ... \n",
"19 two hatchback fwd front 94.5 ... \n",
"20 four sedan fwd front 94.5 ... \n",
"\n",
" engine-size fuel-system bore stroke compression-ratio horsepower \\\n",
"0 130 mpfi 3.47 2.68 9.0 111 \n",
"1 130 mpfi 3.47 2.68 9.0 111 \n",
"2 152 mpfi 2.68 3.47 9.0 154 \n",
"3 109 mpfi 3.19 3.40 10.0 102 \n",
"4 136 mpfi 3.19 3.40 8.0 115 \n",
"5 136 mpfi 3.19 3.40 8.5 110 \n",
"6 136 mpfi 3.19 3.40 8.5 110 \n",
"7 136 mpfi 3.19 3.40 8.5 110 \n",
"8 131 mpfi 3.13 3.40 8.3 140 \n",
"10 108 mpfi 3.50 2.80 8.8 101 \n",
"11 108 mpfi 3.50 2.80 8.8 101 \n",
"12 164 mpfi 3.31 3.19 9.0 121 \n",
"13 164 mpfi 3.31 3.19 9.0 121 \n",
"14 164 mpfi 3.31 3.19 9.0 121 \n",
"15 209 mpfi 3.62 3.39 8.0 182 \n",
"16 209 mpfi 3.62 3.39 8.0 182 \n",
"17 209 mpfi 3.62 3.39 8.0 182 \n",
"18 61 2bbl 2.91 3.03 9.5 48 \n",
"19 90 2bbl 3.03 3.11 9.6 70 \n",
"20 90 2bbl 3.03 3.11 9.6 70 \n",
"\n",
" peak-rpm city-mpg highway-mpg price \n",
"0 5000 21 27 13495 \n",
"1 5000 21 27 16500 \n",
"2 5000 19 26 16500 \n",
"3 5500 24 30 13950 \n",
"4 5500 18 22 17450 \n",
"5 5500 19 25 15250 \n",
"6 5500 19 25 17710 \n",
"7 5500 19 25 18920 \n",
"8 5500 17 20 23875 \n",
"10 5800 23 29 16430 \n",
"11 5800 23 29 16925 \n",
"12 4250 21 28 20970 \n",
"13 4250 21 28 21105 \n",
"14 4250 20 25 24565 \n",
"15 5400 16 22 30760 \n",
"16 5400 16 22 41315 \n",
"17 5400 15 20 36880 \n",
"18 5100 47 53 5151 \n",
"19 5400 38 43 6295 \n",
"20 5400 38 43 6575 \n",
"\n",
"[20 rows x 26 columns]"
]
},
"execution_count": 19,
"metadata": {},
"output_type": "execute_result"
}
],
"source": [
"df=df1.dropna(subset=[\"price\"], axis=0)\n",
"df.head(20)"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"Now, we have successfully read the raw dataset and added the correct headers into the dataframe.\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
" <div class=\"alert alert-danger alertdanger\" style=\"margin-top: 20px\">\n",
"<h1> Question #2: </h1>\n",
"<b>Find the name of the columns of the dataframe.</b>\n",
"</div>\n"
]
},
{
"cell_type": "code",
"execution_count": 20,
"metadata": {},
"outputs": [
{
"data": {
"text/plain": [
"Index(['symboling', 'normalized-losses', 'make', 'fuel-type', 'aspiration',\n",
" 'num-of-doors', 'body-style', 'drive-wheels', 'engine-location',\n",
" 'wheel-base', 'length', 'width', 'height', 'curb-weight', 'engine-type',\n",
" 'num-of-cylinders', 'engine-size', 'fuel-system', 'bore', 'stroke',\n",
" 'compression-ratio', 'horsepower', 'peak-rpm', 'city-mpg',\n",
" 'highway-mpg', 'price'],\n",
" dtype='object')"
]
},
"execution_count": 20,
"metadata": {},
"output_type": "execute_result"
}
],
"source": [
"# Write your code below and press Shift+Enter to execute \n",
"df1.columns"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<details><summary>Click here for the solution</summary>\n",
"\n",
"```python\n",
"print(df.columns)\n",
"```\n",
"\n",
"</details>\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<h2>Save Dataset</h2>\n",
"<p>\n",
"Correspondingly, Pandas enables us to save the dataset to csv. By using the <code>dataframe.to_csv()</code> method, you can add the file path and name along with quotation marks in the brackets.\n",
"</p>\n",
"<p>\n",
"For example, if you would save the dataframe <b>df</b> as <b>automobile.csv</b> to your local machine, you may use the syntax below, where <code>index = False</code> means the row names will not be written.\n",
"</p>\n"
]
},
{
"cell_type": "raw",
"metadata": {},
"source": [
"df.to_csv(\"automobile.csv\", index=False)"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"We can also read and save other file formats. We can use similar functions like **`pd.read_csv()`** and **`df.to_csv()`** for other data formats. The functions are listed in the following table:\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<h2>Read/Save Other Data Formats</h2>\n",
"\n",
"| Data Formate | Read | Save |\n",
"| ------------ | :---------------: | --------------: |\n",
"| csv | `pd.read_csv()` | `df.to_csv()` |\n",
"| json | `pd.read_json()` | `df.to_json()` |\n",
"| excel | `pd.read_excel()` | `df.to_excel()` |\n",
"| hdf | `pd.read_hdf()` | `df.to_hdf()` |\n",
"| sql | `pd.read_sql()` | `df.to_sql()` |\n",
"| ... | ... | ... |\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<h1 id=\"basic_insight\">Basic Insight of Dataset</h1>\n",
"<p>\n",
"After reading data into Pandas dataframe, it is time for us to explore the dataset.<br>\n",
"\n",
"There are several ways to obtain essential insights of the data to help us better understand our dataset.\n",
"\n",
"</p>\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<h2>Data Types</h2>\n",
"<p>\n",
"Data has a variety of types.<br>\n",
"\n",
"The main types stored in Pandas dataframes are <b>object</b>, <b>float</b>, <b>int</b>, <b>bool</b> and <b>datetime64</b>. In order to better learn about each attribute, it is always good for us to know the data type of each column. In Pandas:\n",
"\n",
"</p>\n"
]
},
{
"cell_type": "code",
"execution_count": 21,
"metadata": {},
"outputs": [
{
"data": {
"text/plain": [
"symboling int64\n",
"normalized-losses object\n",
"make object\n",
"fuel-type object\n",
"aspiration object\n",
"num-of-doors object\n",
"body-style object\n",
"drive-wheels object\n",
"engine-location object\n",
"wheel-base float64\n",
"length float64\n",
"width float64\n",
"height float64\n",
"curb-weight int64\n",
"engine-type object\n",
"num-of-cylinders object\n",
"engine-size int64\n",
"fuel-system object\n",
"bore object\n",
"stroke object\n",
"compression-ratio float64\n",
"horsepower object\n",
"peak-rpm object\n",
"city-mpg int64\n",
"highway-mpg int64\n",
"price object\n",
"dtype: object"
]
},
"execution_count": 21,
"metadata": {},
"output_type": "execute_result"
}
],
"source": [
"df.dtypes\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"A series with the data type of each column is returned.\n"
]
},
{
"cell_type": "code",
"execution_count": 22,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"symboling int64\n",
"normalized-losses object\n",
"make object\n",
"fuel-type object\n",
"aspiration object\n",
"num-of-doors object\n",
"body-style object\n",
"drive-wheels object\n",
"engine-location object\n",
"wheel-base float64\n",
"length float64\n",
"width float64\n",
"height float64\n",
"curb-weight int64\n",
"engine-type object\n",
"num-of-cylinders object\n",
"engine-size int64\n",
"fuel-system object\n",
"bore object\n",
"stroke object\n",
"compression-ratio float64\n",
"horsepower object\n",
"peak-rpm object\n",
"city-mpg int64\n",
"highway-mpg int64\n",
"price object\n",
"dtype: object\n"
]
}
],
"source": [
"# check the data type of data frame \"df\" by .dtypes\n",
"print(df.dtypes)"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<p>\n",
"As shown above, it is clear to see that the data type of \"symboling\" and \"curb-weight\" are <code>int64</code>, \"normalized-losses\" is <code>object</code>, and \"wheel-base\" is <code>float64</code>, etc.\n",
"</p>\n",
"<p>\n",
"These data types can be changed; we will learn how to accomplish this in a later module.\n",
"</p>\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<h2>Describe</h2>\n",
"If we would like to get a statistical summary of each column e.g. count, column mean value, column standard deviation, etc., we use the describe method:\n"
]
},
{
"cell_type": "raw",
"metadata": {},
"source": [
"dataframe.describe()"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"This method will provide various summary statistics, excluding <code>NaN</code> (Not a Number) values.\n"
]
},
{
"cell_type": "code",
"execution_count": 23,
"metadata": {},
"outputs": [
{
"data": {
"text/html": [
"<div>\n",
"<style scoped>\n",
" .dataframe tbody tr th:only-of-type {\n",
" vertical-align: middle;\n",
" }\n",
"\n",
" .dataframe tbody tr th {\n",
" vertical-align: top;\n",
" }\n",
"\n",
" .dataframe thead th {\n",
" text-align: right;\n",
" }\n",
"</style>\n",
"<table border=\"1\" class=\"dataframe\">\n",
" <thead>\n",
" <tr style=\"text-align: right;\">\n",
" <th></th>\n",
" <th>symboling</th>\n",
" <th>wheel-base</th>\n",
" <th>length</th>\n",
" <th>width</th>\n",
" <th>height</th>\n",
" <th>curb-weight</th>\n",
" <th>engine-size</th>\n",
" <th>compression-ratio</th>\n",
" <th>city-mpg</th>\n",
" <th>highway-mpg</th>\n",
" </tr>\n",
" </thead>\n",
" <tbody>\n",
" <tr>\n",
" <th>count</th>\n",
" <td>201.000000</td>\n",
" <td>201.000000</td>\n",
" <td>201.000000</td>\n",
" <td>201.000000</td>\n",
" <td>201.000000</td>\n",
" <td>201.000000</td>\n",
" <td>201.000000</td>\n",
" <td>201.000000</td>\n",
" <td>201.000000</td>\n",
" <td>201.000000</td>\n",
" </tr>\n",
" <tr>\n",
" <th>mean</th>\n",
" <td>0.840796</td>\n",
" <td>98.797015</td>\n",
" <td>174.200995</td>\n",
" <td>65.889055</td>\n",
" <td>53.766667</td>\n",
" <td>2555.666667</td>\n",
" <td>126.875622</td>\n",
" <td>10.164279</td>\n",
" <td>25.179104</td>\n",
" <td>30.686567</td>\n",
" </tr>\n",
" <tr>\n",
" <th>std</th>\n",
" <td>1.254802</td>\n",
" <td>6.066366</td>\n",
" <td>12.322175</td>\n",
" <td>2.101471</td>\n",
" <td>2.447822</td>\n",
" <td>517.296727</td>\n",
" <td>41.546834</td>\n",
" <td>4.004965</td>\n",
" <td>6.423220</td>\n",
" <td>6.815150</td>\n",
" </tr>\n",
" <tr>\n",
" <th>min</th>\n",
" <td>-2.000000</td>\n",
" <td>86.600000</td>\n",
" <td>141.100000</td>\n",
" <td>60.300000</td>\n",
" <td>47.800000</td>\n",
" <td>1488.000000</td>\n",
" <td>61.000000</td>\n",
" <td>7.000000</td>\n",
" <td>13.000000</td>\n",
" <td>16.000000</td>\n",
" </tr>\n",
" <tr>\n",
" <th>25%</th>\n",
" <td>0.000000</td>\n",
" <td>94.500000</td>\n",
" <td>166.800000</td>\n",
" <td>64.100000</td>\n",
" <td>52.000000</td>\n",
" <td>2169.000000</td>\n",
" <td>98.000000</td>\n",
" <td>8.600000</td>\n",
" <td>19.000000</td>\n",
" <td>25.000000</td>\n",
" </tr>\n",
" <tr>\n",
" <th>50%</th>\n",
" <td>1.000000</td>\n",
" <td>97.000000</td>\n",
" <td>173.200000</td>\n",
" <td>65.500000</td>\n",
" <td>54.100000</td>\n",
" <td>2414.000000</td>\n",
" <td>120.000000</td>\n",
" <td>9.000000</td>\n",
" <td>24.000000</td>\n",
" <td>30.000000</td>\n",
" </tr>\n",
" <tr>\n",
" <th>75%</th>\n",
" <td>2.000000</td>\n",
" <td>102.400000</td>\n",
" <td>183.500000</td>\n",
" <td>66.600000</td>\n",
" <td>55.500000</td>\n",
" <td>2926.000000</td>\n",
" <td>141.000000</td>\n",
" <td>9.400000</td>\n",
" <td>30.000000</td>\n",
" <td>34.000000</td>\n",
" </tr>\n",
" <tr>\n",
" <th>max</th>\n",
" <td>3.000000</td>\n",
" <td>120.900000</td>\n",
" <td>208.100000</td>\n",
" <td>72.000000</td>\n",
" <td>59.800000</td>\n",
" <td>4066.000000</td>\n",
" <td>326.000000</td>\n",
" <td>23.000000</td>\n",
" <td>49.000000</td>\n",
" <td>54.000000</td>\n",
" </tr>\n",
" </tbody>\n",
"</table>\n",
"</div>"
],
"text/plain": [
" symboling wheel-base length width height \\\n",
"count 201.000000 201.000000 201.000000 201.000000 201.000000 \n",
"mean 0.840796 98.797015 174.200995 65.889055 53.766667 \n",
"std 1.254802 6.066366 12.322175 2.101471 2.447822 \n",
"min -2.000000 86.600000 141.100000 60.300000 47.800000 \n",
"25% 0.000000 94.500000 166.800000 64.100000 52.000000 \n",
"50% 1.000000 97.000000 173.200000 65.500000 54.100000 \n",
"75% 2.000000 102.400000 183.500000 66.600000 55.500000 \n",
"max 3.000000 120.900000 208.100000 72.000000 59.800000 \n",
"\n",
" curb-weight engine-size compression-ratio city-mpg highway-mpg \n",
"count 201.000000 201.000000 201.000000 201.000000 201.000000 \n",
"mean 2555.666667 126.875622 10.164279 25.179104 30.686567 \n",
"std 517.296727 41.546834 4.004965 6.423220 6.815150 \n",
"min 1488.000000 61.000000 7.000000 13.000000 16.000000 \n",
"25% 2169.000000 98.000000 8.600000 19.000000 25.000000 \n",
"50% 2414.000000 120.000000 9.000000 24.000000 30.000000 \n",
"75% 2926.000000 141.000000 9.400000 30.000000 34.000000 \n",
"max 4066.000000 326.000000 23.000000 49.000000 54.000000 "
]
},
"execution_count": 23,
"metadata": {},
"output_type": "execute_result"
}
],
"source": [
"df.describe()"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<p>\n",
"This shows the statistical summary of all numeric-typed (int, float) columns.<br>\n",
"\n",
"For example, the attribute \"symboling\" has 205 counts, the mean value of this column is 0.83, the standard deviation is 1.25, the minimum value is -2, 25th percentile is 0, 50th percentile is 1, 75th percentile is 2, and the maximum value is 3. <br>\n",
"\n",
"However, what if we would also like to check all the columns including those that are of type object? <br><br>\n",
"\n",
"You can add an argument <code>include = \"all\"</code> inside the bracket. Let's try it again.\n",
"\n",
"</p>\n"
]
},
{
"cell_type": "code",
"execution_count": 24,
"metadata": {},
"outputs": [
{
"data": {
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"<table border=\"1\" class=\"dataframe\">\n",
" <thead>\n",
" <tr style=\"text-align: right;\">\n",
" <th></th>\n",
" <th>symboling</th>\n",
" <th>normalized-losses</th>\n",
" <th>make</th>\n",
" <th>fuel-type</th>\n",
" <th>aspiration</th>\n",
" <th>num-of-doors</th>\n",
" <th>body-style</th>\n",
" <th>drive-wheels</th>\n",
" <th>engine-location</th>\n",
" <th>wheel-base</th>\n",
" <th>...</th>\n",
" <th>engine-size</th>\n",
" <th>fuel-system</th>\n",
" <th>bore</th>\n",
" <th>stroke</th>\n",
" <th>compression-ratio</th>\n",
" <th>horsepower</th>\n",
" <th>peak-rpm</th>\n",
" <th>city-mpg</th>\n",
" <th>highway-mpg</th>\n",
" <th>price</th>\n",
" </tr>\n",
" </thead>\n",
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" <tr>\n",
" <th>count</th>\n",
" <td>201.000000</td>\n",
" <td>164</td>\n",
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" <td>51</td>\n",
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" <td>2</td>\n",
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" <td>8</td>\n",
" <td>38</td>\n",
" <td>36</td>\n",
" <td>NaN</td>\n",
" <td>58</td>\n",
" <td>22</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>186</td>\n",
" </tr>\n",
" <tr>\n",
" <th>top</th>\n",
" <td>NaN</td>\n",
" <td>161</td>\n",
" <td>toyota</td>\n",
" <td>gas</td>\n",
" <td>std</td>\n",
" <td>four</td>\n",
" <td>sedan</td>\n",
" <td>fwd</td>\n",
" <td>front</td>\n",
" <td>NaN</td>\n",
" <td>...</td>\n",
" <td>NaN</td>\n",
" <td>mpfi</td>\n",
" <td>3.62</td>\n",
" <td>3.40</td>\n",
" <td>NaN</td>\n",
" <td>68</td>\n",
" <td>4800</td>\n",
" <td>NaN</td>\n",
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" </tr>\n",
" <tr>\n",
" <th>freq</th>\n",
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" <td>11</td>\n",
" <td>32</td>\n",
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" <td>NaN</td>\n",
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" <td>NaN</td>\n",
" <td>92</td>\n",
" <td>23</td>\n",
" <td>19</td>\n",
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" <td>19</td>\n",
" <td>36</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>2</td>\n",
" </tr>\n",
" <tr>\n",
" <th>mean</th>\n",
" <td>0.840796</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>98.797015</td>\n",
" <td>...</td>\n",
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" <td>NaN</td>\n",
" <td>NaN</td>\n",
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" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>25.179104</td>\n",
" <td>30.686567</td>\n",
" <td>NaN</td>\n",
" </tr>\n",
" <tr>\n",
" <th>std</th>\n",
" <td>1.254802</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>6.066366</td>\n",
" <td>...</td>\n",
" <td>41.546834</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>4.004965</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>6.423220</td>\n",
" <td>6.815150</td>\n",
" <td>NaN</td>\n",
" </tr>\n",
" <tr>\n",
" <th>min</th>\n",
" <td>-2.000000</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>86.600000</td>\n",
" <td>...</td>\n",
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" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
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" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
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" <td>NaN</td>\n",
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" <td>NaN</td>\n",
" <td>NaN</td>\n",
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" <td>NaN</td>\n",
" <td>NaN</td>\n",
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" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
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" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>9.000000</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>24.000000</td>\n",
" <td>30.000000</td>\n",
" <td>NaN</td>\n",
" </tr>\n",
" <tr>\n",
" <th>75%</th>\n",
" <td>2.000000</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>102.400000</td>\n",
" <td>...</td>\n",
" <td>141.000000</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>9.400000</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>30.000000</td>\n",
" <td>34.000000</td>\n",
" <td>NaN</td>\n",
" </tr>\n",
" <tr>\n",
" <th>max</th>\n",
" <td>3.000000</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
" <td>NaN</td>\n",
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" <td>NaN</td>\n",
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" </tr>\n",
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"</table>\n",
"<p>11 rows × 26 columns</p>\n",
"</div>"
],
"text/plain": [
" symboling normalized-losses make fuel-type aspiration \\\n",
"count 201.000000 164 201 201 201 \n",
"unique NaN 51 22 2 2 \n",
"top NaN 161 toyota gas std \n",
"freq NaN 11 32 181 165 \n",
"mean 0.840796 NaN NaN NaN NaN \n",
"std 1.254802 NaN NaN NaN NaN \n",
"min -2.000000 NaN NaN NaN NaN \n",
"25% 0.000000 NaN NaN NaN NaN \n",
"50% 1.000000 NaN NaN NaN NaN \n",
"75% 2.000000 NaN NaN NaN NaN \n",
"max 3.000000 NaN NaN NaN NaN \n",
"\n",
" num-of-doors body-style drive-wheels engine-location wheel-base ... \\\n",
"count 199 201 201 201 201.000000 ... \n",
"unique 2 5 3 2 NaN ... \n",
"top four sedan fwd front NaN ... \n",
"freq 113 94 118 198 NaN ... \n",
"mean NaN NaN NaN NaN 98.797015 ... \n",
"std NaN NaN NaN NaN 6.066366 ... \n",
"min NaN NaN NaN NaN 86.600000 ... \n",
"25% NaN NaN NaN NaN 94.500000 ... \n",
"50% NaN NaN NaN NaN 97.000000 ... \n",
"75% NaN NaN NaN NaN 102.400000 ... \n",
"max NaN NaN NaN NaN 120.900000 ... \n",
"\n",
" engine-size fuel-system bore stroke compression-ratio horsepower \\\n",
"count 201.000000 201 197 197 201.000000 199 \n",
"unique NaN 8 38 36 NaN 58 \n",
"top NaN mpfi 3.62 3.40 NaN 68 \n",
"freq NaN 92 23 19 NaN 19 \n",
"mean 126.875622 NaN NaN NaN 10.164279 NaN \n",
"std 41.546834 NaN NaN NaN 4.004965 NaN \n",
"min 61.000000 NaN NaN NaN 7.000000 NaN \n",
"25% 98.000000 NaN NaN NaN 8.600000 NaN \n",
"50% 120.000000 NaN NaN NaN 9.000000 NaN \n",
"75% 141.000000 NaN NaN NaN 9.400000 NaN \n",
"max 326.000000 NaN NaN NaN 23.000000 NaN \n",
"\n",
" peak-rpm city-mpg highway-mpg price \n",
"count 199 201.000000 201.000000 201 \n",
"unique 22 NaN NaN 186 \n",
"top 4800 NaN NaN 7295 \n",
"freq 36 NaN NaN 2 \n",
"mean NaN 25.179104 30.686567 NaN \n",
"std NaN 6.423220 6.815150 NaN \n",
"min NaN 13.000000 16.000000 NaN \n",
"25% NaN 19.000000 25.000000 NaN \n",
"50% NaN 24.000000 30.000000 NaN \n",
"75% NaN 30.000000 34.000000 NaN \n",
"max NaN 49.000000 54.000000 NaN \n",
"\n",
"[11 rows x 26 columns]"
]
},
"execution_count": 24,
"metadata": {},
"output_type": "execute_result"
}
],
"source": [
"# describe all the columns in \"df\" \n",
"df.describe(include = \"all\")"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<p>\n",
"Now it provides the statistical summary of all the columns, including object-typed attributes.<br>\n",
"\n",
"We can now see how many unique values there, which one is the top value and the frequency of top value in the object-typed columns.<br>\n",
"\n",
"Some values in the table above show as \"NaN\". This is because those numbers are not available regarding a particular column type.<br>\n",
"\n",
"</p>\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<div class=\"alert alert-danger alertdanger\" style=\"margin-top: 20px\">\n",
"<h1> Question #3: </h1>\n",
"\n",
"<p>\n",
"You can select the columns of a dataframe by indicating the name of each column. For example, you can select the three columns as follows:\n",
"</p>\n",
"<p>\n",
" <code>dataframe[[' column 1 ',column 2', 'column 3']]</code>\n",
"</p>\n",
"<p>\n",
"Where \"column\" is the name of the column, you can apply the method \".describe()\" to get the statistics of those columns as follows:\n",
"</p>\n",
"<p>\n",
" <code>dataframe[[' column 1 ',column 2', 'column 3'] ].describe()</code>\n",
"</p>\n",
"\n",
"Apply the method to \".describe()\" to the columns 'length' and 'compression-ratio'.\n",
"\n",
"</div>\n"
]
},
{
"cell_type": "code",
"execution_count": 28,
"metadata": {},
"outputs": [
{
"data": {
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" <th>std</th>\n",
" <td>12.322175</td>\n",
" <td>4.004965</td>\n",
" </tr>\n",
" <tr>\n",
" <th>min</th>\n",
" <td>141.100000</td>\n",
" <td>7.000000</td>\n",
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" <tr>\n",
" <th>25%</th>\n",
" <td>166.800000</td>\n",
" <td>8.600000</td>\n",
" </tr>\n",
" <tr>\n",
" <th>50%</th>\n",
" <td>173.200000</td>\n",
" <td>9.000000</td>\n",
" </tr>\n",
" <tr>\n",
" <th>75%</th>\n",
" <td>183.500000</td>\n",
" <td>9.400000</td>\n",
" </tr>\n",
" <tr>\n",
" <th>max</th>\n",
" <td>208.100000</td>\n",
" <td>23.000000</td>\n",
" </tr>\n",
" </tbody>\n",
"</table>\n",
"</div>"
],
"text/plain": [
" length compression-ratio\n",
"count 201.000000 201.000000\n",
"mean 174.200995 10.164279\n",
"std 12.322175 4.004965\n",
"min 141.100000 7.000000\n",
"25% 166.800000 8.600000\n",
"50% 173.200000 9.000000\n",
"75% 183.500000 9.400000\n",
"max 208.100000 23.000000"
]
},
"execution_count": 28,
"metadata": {},
"output_type": "execute_result"
}
],
"source": [
"# Write your code below and press Shift+Enter to execute \n",
"df[['length','compression-ratio']].describe()"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<details><summary>Click here for the solution</summary>\n",
"\n",
"```python\n",
"df[['length', 'compression-ratio']].describe()\n",
"```\n",
"\n",
"</details>\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<h2>Info</h2>\n",
"Another method you can use to check your dataset is:\n"
]
},
{
"cell_type": "raw",
"metadata": {},
"source": [
"dataframe.info()"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"It provides a concise summary of your DataFrame.\n",
"\n",
"This method prints information about a DataFrame including the index dtype and columns, non-null values and memory usage.\n"
]
},
{
"cell_type": "code",
"execution_count": 29,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"<class 'pandas.core.frame.DataFrame'>\n",
"Int64Index: 201 entries, 0 to 204\n",
"Data columns (total 26 columns):\n",
" # Column Non-Null Count Dtype \n",
"--- ------ -------------- ----- \n",
" 0 symboling 201 non-null int64 \n",
" 1 normalized-losses 164 non-null object \n",
" 2 make 201 non-null object \n",
" 3 fuel-type 201 non-null object \n",
" 4 aspiration 201 non-null object \n",
" 5 num-of-doors 199 non-null object \n",
" 6 body-style 201 non-null object \n",
" 7 drive-wheels 201 non-null object \n",
" 8 engine-location 201 non-null object \n",
" 9 wheel-base 201 non-null float64\n",
" 10 length 201 non-null float64\n",
" 11 width 201 non-null float64\n",
" 12 height 201 non-null float64\n",
" 13 curb-weight 201 non-null int64 \n",
" 14 engine-type 201 non-null object \n",
" 15 num-of-cylinders 201 non-null object \n",
" 16 engine-size 201 non-null int64 \n",
" 17 fuel-system 201 non-null object \n",
" 18 bore 197 non-null object \n",
" 19 stroke 197 non-null object \n",
" 20 compression-ratio 201 non-null float64\n",
" 21 horsepower 199 non-null object \n",
" 22 peak-rpm 199 non-null object \n",
" 23 city-mpg 201 non-null int64 \n",
" 24 highway-mpg 201 non-null int64 \n",
" 25 price 201 non-null object \n",
"dtypes: float64(5), int64(5), object(16)\n",
"memory usage: 52.4+ KB\n"
]
}
],
"source": [
"# look at the info of \"df\"\n",
"df.info()"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<h1>Excellent! You have just completed the Introduction Notebook!</h1>\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"### Thank you for completing this lab!\n",
"\n",
"## 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-SkillsNetworkCoursesIBMDeveloperSkillsNetworkDA0101ENSkillsNetwork20235326-2021-01-01\" target=\"_blank\">Joseph Santarcangelo</a>\n",
"\n",
"### Other Contributors\n",
"\n",
"<a href=\"https://www.linkedin.com/in/mahdi-noorian-58219234/?utm_medium=Exinfluencer&utm_source=Exinfluencer&utm_content=000026UJ&utm_term=10006555&utm_id=NA-SkillsNetwork-Channel-SkillsNetworkCoursesIBMDeveloperSkillsNetworkDA0101ENSkillsNetwork20235326-2021-01-01\" target=\"_blank\">Mahdi Noorian PhD</a>\n",
"\n",
"Bahare Talayian\n",
"\n",
"Eric Xiao\n",
"\n",
"Steven Dong\n",
"\n",
"Parizad\n",
"\n",
"Hima Vasudevan\n",
"\n",
"<a href=\"https://www.linkedin.com/in/fiorellawever/?utm_medium=Exinfluencer&utm_source=Exinfluencer&utm_content=000026UJ&utm_term=10006555&utm_id=NA-SkillsNetwork-Channel-SkillsNetworkCoursesIBMDeveloperSkillsNetworkDA0101ENSkillsNetwork20235326-2021-01-01\" target=\"_blank\">Fiorella Wenver</a>\n",
"\n",
"<a href=\"https://www.linkedin.com/in/yi-leng-yao-84451275/?utm_medium=Exinfluencer&utm_source=Exinfluencer&utm_content=000026UJ&utm_term=10006555&utm_id=NA-SkillsNetwork-Channel-SkillsNetworkCoursesIBMDeveloperSkillsNetworkDA0101ENSkillsNetwork20235326-2021-01-01\" target=\"_blank\" >Yi Yao</a>.\n",
"\n",
"## Change Log\n",
"\n",
"| Date (YYYY-MM-DD) | Version | Changed By | Change Description |\n",
"| ----------------- | ------- | ---------- | ---------------------------------------- |\n",
"| 2020-10-30 | 2.3 | Lakshmi | Changed URL of the csv |\n",
"| 2020-09-22 | 2.2 | Nayef | Added replace() method to remove '?' |\n",
"| 2020-09-09 | 2.1 | Lakshmi | Made changes in info method of dataframe |\n",
"| 2020-08-27 | 2.0 | Lavanya | Moved lab to course repo in GitLab |\n",
"\n",
"<hr>\n",
"\n",
"## <h3 align=\"center\"> © IBM Corporation 2020. All rights reserved. <h3/>\n"
]
}
],
"metadata": {
"anaconda-cloud": {},
"kernelspec": {
"display_name": "Python",
"language": "python",
"name": "conda-env-python-py"
},
"language_info": {
"codemirror_mode": {
"name": "ipython",
"version": 3
},
"file_extension": ".py",
"mimetype": "text/x-python",
"name": "python",
"nbconvert_exporter": "python",
"pygments_lexer": "ipython3",
"version": "3.6.13"
}
},
"nbformat": 4,
"nbformat_minor": 4
}
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