-m mod : run library module as a script (terminates option list) -O : optimize generated bytecode slightly; also PYTHONOPTIMIZE=x -OO : remove doc-strings in addition to the -O optimizations -R : use a pseudo-random salt to make hash() values of various types be
-Q arg : division options: -Qold (default), -Qwarn, -Qwarnall, -Qnew -s : don't add user site directory to sys.path; also PYTHONNOUSERSITE -S : don't imply 'import site' on initialization -t : issue warnings about inconsistent tab usage (-tt: issue errors) -u : unbuffered binary stdout and stderr; also PYTHONUNBUFFERED=x
-v : verbose (trace import statements); also PYTHONVERBOSE=x
-V : print the Python version number and exit (also --version) -W arg : warning control; arg is action:message:category:module:lineno
-x : skip first line of source, allowing use of non-Unix forms of #!cmd -3 : warn about Python 3.x incompatibilities that 2to3 cannot trivially fix file : program read from script file - : program read from stdin (default; interactive mode if a tty) arg ...: arguments passed to program in sys.argv[1:]
Other environment variables: PYTHONSTARTUP: file executed on interactive startup (no default) PYTHONPATH : ':'-separated list of directories prefixed to the
PYTHONHOME : alternate <prefix> directory (or <prefix>:<exec_prefix>).
PYTHONCASEOK : ignore case in 'import' statements (Windows). PYTHONIOENCODING: Encoding[:errors] used for stdin/stdout/stderr. PYTHONHASHSEED: if this variable is set to 'random', the effect is the same