the path setting lists set of directories that the operating system searches for executable programswhen they are invoked without full directory path it should normally include the directory where your python interpreter lives (the python program on unixor the python exe file on windowsyou don' need to set this variable at all if you are willing to work in the directory where python residesor type the full path to python in command lines on windowsfor instancethe path is irrelevant if you run cd :\python before running any code (to change to the directory where python lives--though you shouldn' generally store your own code in this directory per )or always type :\python \python instead of just python (giving full pathalso note that path settings are mostly for launching programs from command linesthey are usually irrelevant when launching via icon clicks and ides--the former uses filename associationsand the latter uses built-in mechanismsand doesn' generally require this configuration step see also appendix for details on ' automatic path setting option at install time pythonpath the pythonpath setting serves role similar to paththe python interpreter consults the pythonpath variable to locate module files when you import them in program if usedthis variable is set to platform-dependent list of directory namesseparated by colons on unix and semicolons on windows this list normally includes just your own source code directories its content is merged into the sys path module import search pathalong with the script' container directoryany pth path file settingsand standard library directories you don' need to set this variable unless you will be performing cross-directory imports--because python always searches the home directory of the program' toplevel file automaticallythis setting is required only if module needs to import another module that lives in different directory see also the discussion of pth path files later in this appendix for an alternative to pythonpath for more on the module search pathrefer to pythonstartup if pythonstartup is set to the pathname of file of python codepython executes the file' code automatically whenever you start the interactive interpreteras though you had typed it at the interactive command line this is rarely used but handy way to make sure you always load certain utilities when working interactivelyit saves an import each time you start python session tkinter settings if you wish to use the tkinter gui toolkit (named tkinter in )you might have to set the two gui variables in the last line of table - to the names of the source library directories of the tcl and tk systems (much like pythonpathhoweverthese settings are not required on windows systems (where tkinter support is installed alongside python)and are usually not required on mac os and linux appendix ainstallation and configuration