Lecture 2

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# Lecture 2
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## **DANL 100: Programming for Data Analytics**
### Byeong-Hak Choe
### Septermber 1, 2022

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# Announcement

### Changes in Office Hours

- Office: South Hall 117B.
- Office Hours: 
  - Mondays 3:30 PM-5:30 PM 
  - Wednesdays 1:30 PM-3:30 PM.

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# Installing the Tools
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# Installing the Tools
### R programming

The R language is available as a free download from the R Project website at:

- Windows: [https://cran.r-project.org/bin/windows/base/](https://cran.r-project.org/bin/windows/base/)
- Mac: [https://cran.r-project.org/bin/macosx/](https://cran.r-project.org/bin/macosx/)
  -  Download the file of R that corresponds to your Mac OS (Big Sur, Apple silicon arm64, High Sierra, El Capitan, Mavericks, etc.)

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# Installing the Tools
### RStudio

- **RStudio** offers a graphical interface to assist in creating R code:

- The RStudio Desktop is available as a free download from the following webpage:
    - [https://www.rstudio.com/products/rstudio/download/#download](https://www.rstudio.com/products/rstudio/download/#download)

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# Installing the Tools
### Excel

- If you have not installed Microsoft Office on your computer, visit [software.geneseo.edu](https://wiki.geneseo.edu/display/cit/Software+at+Geneseo#SoftwareatGeneseo-MicrosoftOffice).
  - Download and install Microsoft Office from the software.geneseo.edu.

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# Installing the Tools
### Anaconda

- Anaconda is an all-in-one Python distribution.
  - Anaconda includes Python 3.x and its standard modules such as pip, pandas, matplotlib, etc.
  - Anaconda also includes several software applications of integrated development environment (IDE), which is a software for editing codes.
  - For the Python code, we will use **Spyder** IDE.  
    - Do not use RStudio from Anaconda, because RStudio from Anaconda is out-dated.

- To install Anaconda, go to the following download page:
  - [https://www.anaconda.com/products/distribution](https://www.anaconda.com/products/distribution).
  - Click the "Download" button.

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# Installing the Tools
### Spyder IDE

- If Spyder IDE from Anaconda is lagging, consider installing it additionally.
  
- To install Spyder IDE in addition to Anaconda, go to the following download page:
  - [https://www.spyder-ide.org](https://www.spyder-ide.org).
  - Click the "DOWNLOAD" menu.

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# Survey

- While installing the tools, click and take the following survey:
  - [DANL 100 Survey](https://forms.gle/T63P6h16HbKSbuMh9).

- Submit the survey before the class ends.
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# Installing the Tools
### Spyder Environment 
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<img src="../lec_figs/spyder_env.png" width="100%" style="display: block; margin: auto;" />
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- Red box is **Script Editor** where you can create, open and edit files.

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# Installing the Tools
### Spyder Environment 
.pull-left[
<img src="../lec_figs/spyder_env.png" width="100%" style="display: block; margin: auto;" />
]

.pull-right[
- Blue box is **Console Pane** that allows you to interact directly with the Python interpreter and type commands where Python will immediately execute them.

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# Installing the Tools
### Spyder Environment 
.pull-left[
<img src="../lec_figs/spyder_env.png" width="100%" style="display: block; margin: auto;" />
]

.pull-right[
- Yellow box is **Variable Explorer** where you can see the values of variables, data frames, and other objects that are currently stored in memory.
  - Double-clicking a variable will open a specialized viewer, allowing you to inspect its contents.

]

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# Management of Files, Directories, and Scripts
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# Management of Files, Directories, and Scripts
### Some materials for data

- The following page has some materials of R codes and data files: [https://github.com/WinVector/PDSwR2](https://github.com/WinVector/PDSwR2).

.panelset[

.panel[.panel-name[Windows]

- **Step 1.** Go to your Download folder (or the folder where the downloaded file is saved) using the File Explorer.
- **Step 2.** Click the ZIP file.
- **Step 3.** Cut the file by using the shortcut (**Ctrl+X**).  
- **Step 4.** Go to your working directory for the course using the File Explorer.
- **Step 5.** Paste the file to your working directory by using the shortcut (**Ctrl+V**).
- **Step 6.** Right-click the ZIP file and click "Extract ..."
]

.panel[.panel-name[Mac]

- **Step 1.** Go to your Download directory (or the directory where the downloaded file is saved) using the File Explorer.
- **Step 2.** Click the ZIP file (or the directory if the ZIP file is extracted).
- **Step 3.** Copy the file (or the directory) by using the shortcut (**command+C**). 
- **Step 4.** Go to your working directory for the course using the Finder.
- **Step 5.** Paste the file (or the directory) to your working directory by using the shortcut (**command+option+V**).
- **Step 6.** Right-click the ZIP file and click "Extract ..."
]

]

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# Management of Files and Directories
### Finding the path name of the file

.panelset[

.panel[.panel-name[Windows 11]

- **Step 1.** Go to your folder using the File Explorer.
- **Step 2.** Right-click the file.
- **Step 3.** Click "Copy as path".
- **Step 4.** Paste the path name of the file to the R script (Ctrl+V).
- **Step 5.** 
  - *Option 1.* Replace backslash(`\`) with double-backslash(`\\`) in the path name.
  - *Option 2.* Replace backslash(`\`) with slash(`/`) in the path name.
]

.panel[.panel-name[Windows 10]

- **Step 1.** Go to your folder using the File Explorer.
- **Step 2.** Keep pressing the "Shift" key
- **Step 3.** Right-click the file.
- **Step 4.** Click "Copy as path".
- **Step 5.** Paste the path name of the file to the Python script in Spyder (Ctrl+V).
- **Step 6.** 
  - *Option 1.* Replace backslash(`\`) with double-backslash(`\\`) in the path name.
  - *Option 2.* Replace backslash(`\`) with slash(`/`) in the path name.
]

.panel[.panel-name[Mac]

- **Step 1.** Go to your folder using the Finder.
- **Step 2.** Right-click the file in the folder
- **Step 3.** Keep pressing "option"
- **Step 4.** Click "Copy 'PATH\_FOR\_YOUR\_FILE' as Pathname" from the menu.
- **Step 5.** Paste it to the the Python script in Spyder (command+V).

]

]

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# Management of Files, Directories, and Scripts
### Code and comment style 
- The two main principles for coding and managing data are:
 - Make things easier for your future self.
 - Don't trust your future self.

- The `#` mark is Spyder's comment character.
  - `#` indicates that the rest of the line is to be ignored.
  - Write comments before the line that you want the comment to apply to.

- Consider using block commenting for separating code sections.
  - `#%%` defines a coding block in Spyder.

- Break down long lines and long algebraic expressions.

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# Starting with Python
### Shortcuts 
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### Mac 
- **F9** runs a current line (where the blinking cursor is) or selected lines.
- **command + 1** is the shortcut for #.
- **command + 4** is the shortcut for block comment.
]

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### Windows 
- **F9** runs a current line (where the blinking cursor is) or selected lines.
- **Ctrl + 1** is the shortcut for #.
- **Ctrl + 4** is the shortcut for block comment.
]

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# Working with Data from Files

- Step 1. Find the path name for the file, `car.data.csv`, from the sub-folder, 'UCICar', in the folder, 'PDSwR2-main'.

- Step 2. In the code below, replace 'PATH_NAME_FOR_THE_FILE_car.data.csv' with the path name for the file, `car.data.csv`.

- Step 3. Run the following Python code:

```python
import pandas as pd

path = 'PATH_NAME_FOR_THE_FILE_car.data.csv'

# reading data
uciCar = pd.read_csv(path)
```