Python3 and PyGObject Installation Notes:

We will be using Python version 3 (3.7 is latest release, but 3.4 or
later is fine).  The PyGObject library adds the ability to display
graphics along with other useful routines.  Installing PyGObject (from
the link provided on the homepage, following instructions for your operating
system) will also install Python3.  The installation can be tricky if the
version of Python3 installed along with PyGObject conflicts with another 
version of Python3 that's already on your system.


	   For Windows PC's (tested on 64bit Windows 10)

Visit msys2.org, then download and execute the msys2...exe installer.
Select "Run MSYS2 now" after installation completes and enter the
command 'pacman -Syu' in the terminal window that comes up.  This will
only install some of the files needed.  You need to close the
command-line window and retart it by running C:\msys64\mingw32.exe.
Here, C:\msys64 is the default installation directory, and yes, choose
mingw32 even if you installed the 64 bit version.  When the prompt
shows up in this window, type 'pacman -Su', which installs additional
packages.  Then type

pacman -S mingw-w64-i686-gtk3 mingw-w64-i686-python3-gobject

to install python and pygobject.

After it finishes, test if it works: in the same window, type 'python3'
You should get a >>> prompt: you're now inside the python interpreter.
Type import gi.  If you got an error, then the installation failed and you
will need to make appropriate sacrifices to the systems gods to make ammends.
Exit the python interpreter by typing 'exit()' (or Control-D on some systems).

Pin the msys2 (mingw32.exe) icon to the bottom task bar so you can start
it quickly.  You should execute all python programs from this command window.
The commands available in this window are similar to Linux commands, including
ls, cd, pwd, etc.  Type pwd: you see that you're in /home/username.  However,
when you open an editor to write programs, you need to store it in directory
C:\msys64\home\username.  The windows path is different (the slash is \, not
/) than the Msys path, which runs a Linux-like environment on top of windows.

I recommend Notepad++ for writing programs on Windows PC's:

  https://notepad-plus-plus.org/

You can use 'pacman' to try and install additional software, including:

pacman -S openssh
pacman -S python3-pip

"pip3" is another python package installer


#####
     	 For Mac OS  (Tested on version 10.11.6)

Follow instructions on the PyGObject 'Getting started' homepage

https://pygobject.readthedocs.io/en/latest/getting_started.html

Select Mac OS and following instructions: goto https://brew.sh and
install brew, which is a program that installs other programs.  Open a
terminal.  The operating system may prevent the installation of some
programs for security reasons (because the software is not from
apple).  To temporarily disable the security measure, type in the
terminal

 sudo spctl --master-disable

Install the software, then re-enable the security measure with

 sudo spctl --master-enable

"sudo" means superuser mode and your account must have this privilege
(usually you do), and you'll be prompted for your password.

To install python, execute the 'brew' instructions stated on the
PyGObject homepage:

 brew install pygobject3 gtk+3

Now the next part deals with conflicting versions of Python3 on your system:

Type in the terminal 'brew list python3'.  This will tell you which
directory that PyGOjbect and its version of python3 are installed.  On
my macbook it's in /usr/local/Cellar/python3.7.0/bin.

type 'which python3' in the terminal.  It will print the directory that python3
is executed from. If it is NOT executed from the same directory as given
in the above step, then you're not running the correct version of python3. 
You can either always type in the full path each time you start python, or
do the following:

Run an editor and open the file ~/.bash_profile  (~ is your home directory).
Add the line:

export PATH=/usr/local/Cellar/python3.7.4_1/bin:${PATH}

Save the file, close and restart the terminal, and try 'which python3' again.
Type python3 to enter the interpreter, then type 'import gi' and the >>> prompt
to see if the installation worked.  Type exit() or Control-D to exit the 
interpreter prompt (back to the OS bash prompt).

I recommend the TextMate editor for writing programs on Mac OS:

  https://macromates.com/download

Make sure that the programs you write are in the same directory that
you execute them from.