Python -h

usage: python [option] ... [-c cmd | -m mod | file | -] [arg] ... Options and arguments (and corresponding environment variables):

　　-b           : issue warnings about str(bytes_instance), str(bytearray_instance) and comparing bytes/bytearray with str. (-bb: issue errors)

　　-B          : don't write .py[co] files on import; also PYTHONDONTWRITEBYTECODE=x

　　-c cmd    : program passed in as string (terminates option list)

　　-d          : debug output from parser; also PYTHONDEBUG=x

　　-E          : ignore PYTHON* environment variables (such as PYTHONPATH)

　　-h          : print this help message and exit (also --help)

　　-i           : inspect interactively after running script; forces a prompt even if stdin does not appear to be a terminal; also PYTHONINSPECT=x

　　-I           : isolate Python from the user's environment (implies -E and -s)

　　-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

　　-q         : don't print version and copyright messages on interactive startup

　　-s         : don't add user site directory to sys.path; also PYTHONNOUSERSITE

　　-S         : don't imply 'import site' on initialization

　　-u         : unbuffered binary stdout and stderr, stdin always buffered; also PYTHONUNBUFFERED=x see man page for details on internal buffering relating to '-u'

　　-v         : verbose (trace import statements); also PYTHONVERBOSE=x can be supplied multiple times to increase verbosity

　　-V        : print the Python version number and exit (also --version) when given twice, print more information about the build

　　-W arg : warning control; arg is action:message:category:module:lineno also PYTHONWARNINGS=arg

　　-x         : skip first line of source, allowing use of non-Unix forms of #!cmd

　　-X opt  : set implementation-specific option

　　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 default module search path.  The result is sys.path.

　　PYTHONHOME   : alternate <prefix> directory (or <prefix>;<exec_prefix>). The default module search path uses <prefix>\lib.

　　PYTHONCASEOK : ignore case in 'import' statements (Windows).

　　PYTHONIOENCODING: Encoding[:errors] used for stdin/stdout/stderr.

　　PYTHONFAULTHANDLER: dump the Python traceback on fatal errors.

　　PYTHONHASHSEED: if this variable is set to 'random', a random value is used to seed the hashes of str, bytes and datetime objects. 

　　　　　　　　　　　　 It can also be set to an integer in the range [0,4294967295] to get hash values with a predictable seed.

　　PYTHONMALLOC: set the Python memory allocators and/or install debug hooks on Python memory allocators. Use PYTHONMALLOC=debug to install debug hooks.