Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation. All rights reserved.
C:\Users\CLi>python -h
usage: python [option] … [-c cmd | -m mod | file | -] [arg] …
Options and arguments (and corresponding environment variables):
-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
-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
unpredictable between separate invocations of the interpreter, as
a defense against denial-of-service attacks
-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
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)
-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
-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
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.
PYTHONHASHSEED: if this variable is set to ‘random’, the effect is the same
as specifying the -R option: 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
