October 11 - Intro to Python

Starting

There is a number of ways that we can do this. The simplest one is having the python intepreter coupled with a text editor. This can be a bit tricky for people using the Windows operating system so we will use a neat IDE called PyCharm. At the end you can find some excellent resources to get you started.

Downloading and installing Python 3 on your computer

If you are using a Mac simply head over to the Python website and download the most recent package. Then double-click on the downloaded file to run the Python 3 installer.

If you are using Windows, download the suitable installer from the Python website . Double-click on the installer and on the first screen, check the Add Python 3.x to PATH option and install. This will let you use python in your terminal. Then click the Disable path length limit option to will allow Python to use long path names. If after the installation you type:

$ python

in the terminal and still get an error then you will have to configure this manually. There are good answers here (using PowerShell), at Superuser (be careful no to copy-paste mindlessly what you find on the Internet), and docs.

Checking if things work

Mac users should be able to access interactive mode by just typing:

$ python3

and you should see something like:

$ python3
Python 3.7.0 (v3.7.0:1bf9cc5093, Jun 26 2018, 23:26:24)
[Clang 6.0 (clang-600.0.57)] on darwin
Type "help", "copyright", "credits" or "license" for more 
information.
>>>

Alternatively you can check which version of python you have installed by:

$ python3 -V 

which should return something like the following:

$ python3 -V
Python 3.7.0

On Windows you can type:

C:\> python -V

which should give you the version of python that you are using. If you see something like:

'python' is not recognized as an internal or external command, 
operable program or batch file.

then you need to follow the instructions in the above section to set up your environment properly.

PyCharm and other editors

There is a number of good editors that you can use if you don't want to use PyCharm:

• Atom
• Notepad++
• Sublime Text

As far as PyCharm goes, you can download the free Community version from the JetBrains website. It is fine if you want to use any other IDE but this is the one that we'll be mainly using for demonstrating stuff.

You can find help installing PyCharm here.

You may use Jupyter if you are comfortable with it but it will probably be a bit of a hassle later on. I will try and find some good resources for using Jupyter with SQL and I will post them here.

Resources for learning

There are hundreds of books/videos/websites that you can find if you search for "Python for Beginners". Below you can find some of my favorites:

• Think like a computer scientist is a great book with tons of examples for total beginners.
• A byte of Python is an introductory text for people with no previous programming experience. You should read up to and including control flow.
• Instant Hacking A minimal crash course that's an excellent starting point. He uses Python 2 though so be careful of the little differences.
• CheckIO is a gamified website containing programming tasks.
• The Python-Course.eu website has an extensive tutorial for complete beginners.
• The University of Michigan has a nice class at Coursera. You can enroll to the course and choose to audit for free.

Important: Be sure that you have configured python properly and that you are able to run just the simplest scripts before the next tutorial. We can't afford to lose time trying to set up machines again.