This section introduces Python environment setup details and describes settings that impact Python programs.
The following shell environment variables (among others) are usually important when using Python:
module file search path. If set, it is used to locate modules at run-
time when they’re imported by a Python program -- Python
looks for an imported module file or package directory in each
directory listed on PYTHONPATH, from left to right. Python generally
searches the home directory of a script as well as the Python
standard source code library directory automatically, so you
don’t need to add these. Hint: check
sys.path interactively to see how the path is
truly set up.
An optional Python initialization file. If used, set this variable to the full path-name of a file of Python code (a module) that you want to be run each time the Python interactive command-line interpreter starts up. This is a convenient way to import modules you use frequently when working interactively.
The operating system’s executable
search path variable. It is used to locate program files when you
type their names at a command line without their full directory
paths. Add the directory containing the
interpreter executable file (or else you must retype its directory
path each time).
In addition, users on platforms other than Windows may need to set variables to use Tkinter if Tcl/Tk installations cannot be ...