Python 3 installation

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Note: These notes are still under development. If you find issues, have questions, or have suggestions, please let me know.

Python 2 was discontinued in January 2020. These notes use Python 3.

Python can be downloaded and installed from the official Python site.

I installed Python to the following path.

D:\Python38

Note: In Windows, the C: drive requires special security settings. I have always kept the Windows C: drive as a code drive and the Windows D: drive (created) as a data drive.

In the examples below, change the paths to fit your paths.

You can also run Python from a portable hard drive or flash drive.

I plugged a portable hard drive into a lab computer in KEC 119 and was able to run Python from the portable hard drive. In KEC 119 my portable hard drive mounted as drive D:.

The package manager for Python is pip.exe. For Python 3, one should use pip3.exe.

D:\Python38\Scripts\pip3.exe

One often gets an error message that pip should be updated. Here is an example message, on 2019-12-18.

WARNING: You are using pip version 19.2.3, however version 19.3.1 is available. You should consider upgrading via the 'python -m pip install --upgrade pip' command

Here is the command I used to upgrade pip.

D:\Python38\python.exe -m pip install --upgrade pip

Here is some of the output on 2019-12-18.

Installing collected packages: pip Found existing installation: pip 19.2.3 Uninstalling pip-19.2.3: Successfully uninstalled pip-19.2.3 Successfully installed pip-19.3.1

The PIL imaging library is used for many Python imaging tasks. Here is the command to install.

D:\Python38\Scripts\pip3.exe install pillow

Here is some of the output on 2019-12-18.

Installing collected packages: pillow Successfully installed pillow-6.2.1

Other packages are installed in the same manner.

For the data science course, the following Python packages are useful. Here are some of the commands.

D:\Python38\Scripts\pip3.exe install matplotlib D:\Python38\Scripts\pip3.exe install pillow D:\Python38\Scripts\pip3.exe install numpy D:\Python38\Scripts\pip3.exe install scipy D:\Python38\Scripts\pip3.exe install pandas D:\Python38\Scripts\pip3.exe install gensim D:\Python38\Scripts\pip3.exe install nltk D:\Python38\Scripts\pip3.exe install scikit-learn

(I will expand on each of these packages over time to explain more about each) We may get to the following.

D:\Python38\Scripts\pip3.exe install jupyterlab

Python can be run from the command line.

Pip can be run from the command line.

In Windows 10, the command line has been replaced with PowerShell. To get the command line back, try the following.

Press Windows-I to open the settings app.
Select "Personalization".
Find the toggle for "Replace Command Prompt with Windows PowerShell in the menu when I right-click the start button or press Windows key+X" and turn it "Off".

Now one can select Windows-X (power users menu) and select "Command prompt".

It can be useful to select the icon in the taskbar and select "Pin to taskbar" to make it easier to start in the future.

Idle is the default (and simple) IDE for Python included with Python.

Here as a command to start Idle.

D:\Python38\python.exe D:\Python38\Lib\idlelib\idle.pyw

Note: This command runs python and has it run the idle python code. After this command is run, the command line window cannot be used until Idle is exited. But one can always open another command prompt.