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PYTHON(1)		    General Commands Manual		     PYTHON(1)

       python  - an interpreted, interactive, object-oriented programming lan-

       python [	-d ] [ -E ] [ -h ] [ -i	] [ -m module-name ] [ -O ]
	      [	-Q argument ] [	-S ] [ -t ] [ -u ]
	      [	-v ] [ -V ] [ -W argument ] [ -x ]
	      [	-c command | script | -	] [ arguments ]

       Python is an interpreted, interactive, object-oriented programming lan-
       guage  that  combines  remarkable power with very clear syntax.	For an
       introduction to programming in Python you are referred  to  the	Python
       Tutorial.  The Python Library Reference documents built-in and standard
       types, constants, functions and modules.	 Finally, the Python Reference
       Manual describes	the syntax and semantics of the	core language in (per-
       haps too) much detail.  (These documents	may be located via the	INTER-
       NET RESOURCES below; they may be	installed on your system as well.)

       Python's	basic power can	be extended with your own modules written in C
       or C++.	On most	 systems  such	modules	 may  be  dynamically  loaded.
       Python is also adaptable	as an extension	language for existing applica-
       tions.  See the internal	documentation for hints.

       Documentation for installed Python modules and packages can  be	viewed
       by running the pydoc program.

       -c command
	      Specify  the command to execute (see next	section).  This	termi-
	      nates the	option list (following options are passed as arguments
	      to the command).

       -d     Turn  on parser debugging	output (for wizards only, depending on
	      compilation options).

       -E     Ignore environment variables like	PYTHONPATH and PYTHONHOME that
	      modify the behavior of the interpreter.

       -h     Prints the usage for the interpreter executable and exits.

       -i     When  a  script  is passed as first argument or the -c option is
	      used, enter interactive mode after executing the script  or  the
	      command.	It does	not read the $PYTHONSTARTUP file.  This	can be
	      useful to	inspect	global variables  or  a	 stack	trace  when  a
	      script raises an exception.

       -m module-name
	      Searches	sys.path for the named module and runs the correspond-
	      ing .py file as a	script.

       -O     Turn on basic optimizations.  This changes the  filename	exten-
	      sion  for	 compiled  (bytecode)  files from .pyc to .pyo.	 Given
	      twice, causes docstrings to be discarded.

       -Q argument
	      Division control;	see PEP	238.  The  argument  must  be  one  of
	      "old"  (the  default,  int/int  and  long/long  return an	int or
	      long), "new" (new	division semantics, i.e. int/int and long/long
	      returns  a float), "warn"	(old division semantics	with a warning
	      for int/int and long/long), or "warnall" (old division semantics
	      with a warning for all use of the	division operator).  For a use
	      of "warnall", see	the Tools/scripts/ script.

       -S     Disable the import of the	module site and	the site-dependent ma-
	      nipulations of sys.path that it entails.

       -t     Issue a warning when a source file mixes tabs and	spaces for in-
	      dentation	in a way that makes it depend on the worth  of	a  tab
	      expressed	 in  spaces.   Issue an	error when the option is given

       -u     Force stdin, stdout and stderr to	 be  totally  unbuffered.   On
	      systems  where  it matters, also put stdin, stdout and stderr in
	      binary mode.  Note that there is internal	 buffering  in	xread-
	      lines(),	readlines()  and  file-object  iterators ("for line in
	      sys.stdin") which	is not influenced by  this  option.   To  work
	      around  this, you	will want to use "sys.stdin.readline()"	inside
	      a	"while 1:" loop.

       -v     Print a message each time	a module is initialized,  showing  the
	      place  (filename	or  built-in  module) from which it is loaded.
	      When given twice,	print a	message	for each file that is  checked
	      for  when	 searching for a module.  Also provides	information on
	      module cleanup at	exit.

       -V     Prints the Python	version	number of the executable and exits.

       -W argument
	      Warning control.	Python sometimes  prints  warning  message  to
	      sys.stderr.   A  typical warning message has the following form:
	      file:line: category:  message.   By  default,  each  warning  is
	      printed  once for	each source line where it occurs.  This	option
	      controls how often warnings are printed.	 Multiple  -W  options
	      may  be  given; when a warning matches more than one option, the
	      action for the last matching option is  performed.   Invalid  -W
	      options  are ignored (a warning message is printed about invalid
	      options when the first warning is	issued).  Warnings can also be
	      controlled  from within a	Python program using the warnings mod-

	      The simplest form	of argument is one  of	the  following	action
	      strings  (or  a unique abbreviation): ignore to ignore all warn-
	      ings; default to explicitly request the default behavior (print-
	      ing  each	 warning once per source line);	all to print a warning
	      each time	it occurs (this	may generate many messages if a	 warn-
	      ing  is  triggered  repeatedly for the same source line, such as
	      inside a loop); module to	print each warning only	only the first
	      time  it	occurs in each module; once to print each warning only
	      the first	time it	occurs in the program; or error	 to  raise  an
	      exception	instead	of printing a warning message.

	      The   full  form	of  argument  is  action:message:category:mod-
	      ule:line.	 Here, action is as explained above but	 only  applies
	      to messages that match the remaining fields.  Empty fields match
	      all values; trailing empty fields	may be omitted.	  The  message
	      field  matches  the  start  of the warning message printed; this
	      match is case-insensitive.  The category field matches the warn-
	      ing category.  This must be a class name;	the match test whether
	      the actual warning category of the message is a subclass of  the
	      specified	 warning category.  The	full class name	must be	given.
	      The module field matches the (fully-qualified) module name; this
	      match  is	 case-sensitive.  The line field matches the line num-
	      ber, where zero matches all line numbers and is thus  equivalent
	      to an omitted line number.

       -x     Skip  the	 first line of the source.  This is intended for a DOS
	      specific hack only.  Warning: the	line numbers in	error messages
	      will be off by one!

       The interpreter interface resembles that	of the UNIX shell: when	called
       with standard input connected to	a tty device, it prompts for  commands
       and  executes  them  until an EOF is read; when called with a file name
       argument	or with	a file as standard input,  it  reads  and  executes  a
       script  from  that  file;  when called with -c command, it executes the
       Python statement(s) given as command.  Here command may contain	multi-
       ple  statements	separated by newlines.	Leading	whitespace is signifi-
       cant in Python statements!  In non-interactive mode, the	 entire	 input
       is parsed before	it is executed.

       If  available,  the script name and additional arguments	thereafter are
       passed to the script in the Python variable sys.argv , which is a  list
       of  strings (you	must first import sys to be able to access it).	 If no
       script name is given, sys.argv[0] is an empty string; if	 -c  is	 used,
       sys.argv[0] contains the	string '-c'.  Note that	options	interpreted by
       the Python interpreter itself are not placed in sys.argv.

       In interactive mode, the	primary	prompt is  `>>>';  the	second	prompt
       (which  appears	when a command is not complete)	is `...'.  The prompts
       can be changed by assignment to sys.ps1 or  sys.ps2.   The  interpreter
       quits  when  it	reads an EOF at	a prompt.  When	an unhandled exception
       occurs, a stack trace is	printed	and control  returns  to  the  primary
       prompt;	in  non-interactive mode, the interpreter exits	after printing
       the stack trace.	 The interrupt signal raises the KeyboardInterrupt ex-
       ception;	 other	UNIX  signals  are  not	caught (except that SIGPIPE is
       sometimes ignored, in favor of the IOError exception).  Error  messages
       are written to stderr.

       These are subject to difference depending on local installation conven-
       tions; ${prefix}	 and  ${exec_prefix}  are  installation-dependent  and
       should  be  interpreted as for GNU software; they may be	the same.  The
       default for both	is /usr/local.

	      Recommended location of the interpreter.

	      Recommended locations of the directories containing the standard

	      Recommended  locations of	the directories	containing the include
	      files needed for developing Python extensions and	embedding  the

	      User-specific initialization file	loaded by the user module; not
	      used by default or by most applications.

	      Change the location of the standard Python  libraries.   By  de-
	      fault,  the  libraries are searched in ${prefix}/lib/python<ver-
	      sion> and	 ${exec_prefix}/lib/python<version>,  where  ${prefix}
	      and  ${exec_prefix} are installation-dependent directories, both
	      defaulting to /usr/local.	 When $PYTHONHOME is set to  a	single
	      directory, its value replaces both ${prefix} and ${exec_prefix}.
	      To specify different values for these, set $PYTHONHOME to	${pre-

	      Augments	the  default search path for module files.  The	format
	      is the same as the shell's $PATH:	one or	more  directory	 path-
	      names   separated	  by  colons.	Non-existent  directories  are
	      silently ignored.	 The default search path is  installation  de-
	      pendent, but generally begins with ${prefix}/lib/python<version>
	      (see PYTHONHOME above).  The default search path is  always  ap-
	      pended  to  $PYTHONPATH.	If a script argument is	given, the di-
	      rectory containing the script is inserted	in the path  in	 front
	      of  $PYTHONPATH.	The search path	can be manipulated from	within
	      a	Python program as the variable sys.path	.

	      If this is the name of a readable	file, the Python  commands  in
	      that  file  are executed before the first	prompt is displayed in
	      interactive mode.	 The file is executed in the same  name	 space
	      where  interactive commands are executed so that objects defined
	      or imported in it	can be used without qualification in  the  in-
	      teractive	 session.  You can also	change the prompts sys.ps1 and
	      sys.ps2 in this file.

	      Set this to a non-empty string to	cause the time module  to  re-
	      quire  dates specified as	strings	to include 4-digit years, oth-
	      erwise 2-digit years are converted based on rules	 described  in
	      the time module documentation.

	      If  this is set to a non-empty string it is equivalent to	speci-
	      fying the	-O option. If set to an	integer, it is	equivalent  to
	      specifying -O multiple times.

	      If  this is set to a non-empty string it is equivalent to	speci-
	      fying the	-d option. If set to an	integer, it is	equivalent  to
	      specifying -d multiple times.

	      If  this is set to a non-empty string it is equivalent to	speci-
	      fying the	-i option.

	      If this is set to	a non-empty string it is equivalent to	speci-
	      fying the	-u option.

	      If  this is set to a non-empty string it is equivalent to	speci-
	      fying the	-v option. If set to an	integer, it is	equivalent  to
	      specifying -v multiple times.

       The Python Software Foundation:

       Main website:
       Community website:
       Developer resources:
       Module repository:
       Newsgroups:  comp.lang.python, comp.lang.python.announce

       Python  is distributed under an Open Source license.  See the file "LI-
       CENSE" in the Python source distribution	for  information  on  terms  &
       conditions  for	accessing  and	otherwise  using Python	and for	a DIS-

	     $Date: 2005-03-20 15:16:03	+0100 (Sun, 20 Mar 2005) $   PYTHON(1)


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