PYTHON linux command manual

PYTHON(1)                                                      PYTHON(1)



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

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

DESCRIPTION
       Python is an  interpreted,  interactive,  object-oriented  programming
       language  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 lan-
       guage in (perhaps too) much detail.  (These documents may  be  located
       via the INTERNET 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  appli-
       cations.  See the internal documentation for hints.

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

COMMAND LINE OPTIONS
       -c command
              Specify the command to execute (see next section).  This termi-
              nates  the  option  list (following options are passed as argu-
              ments 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.

       -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  divi-
              sion semantics with a warning for all use of the division oper-
              ator).  For a use of "warnall", see the Tools/scripts/fixdiv.py
              script.

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

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

       -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
              module.

              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
              (printing each warning once per source line); all  to  print  a
              warning each time it occurs (this may generate many messages if
              a warning 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
              warning category.  This must be a class name;  the  match  test
              whether  the  actual  warning category of the message is a sub-
              class 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  number, 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 mes-
              sages will be off by one!

INTERPRETER INTERFACE
       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 exe-
       cutes a script from that file; when called with -c  command,  it  exe-
       cutes the Python statement(s) given as command.  Here command may con-
       tain multiple statements separated by newlines.  Leading whitespace is
       significant in Python statements!  In non-interactive mode, the entire
       input is parsed befored 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
       exception; other UNIX signals are not caught (except that  SIGPIPE  is
       sometimes ignored, in favor of the IOError exception).  Error messages
       are written to stderr.

FILES AND DIRECTORIES
       These are subject to difference depending on local  installation  con-
       ventions;  ${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.

       ${exec_prefix}/bin/python
              Recommended location of the interpreter.

       ${prefix}/lib/python
       ${exec_prefix}/lib/python
              Recommended  locations  of the directories containing the stan-
              dard modules.

       ${prefix}/include/python
       ${exec_prefix}/include/python
              Recommended locations of the directories containing the include
              files needed for developing Python extensions and embedding the
              interpreter.

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

ENVIRONMENT VARIABLES
       PYTHONHOME
              Change  the  location  of  the  standard  Python libraries.  By
              default,    the    libraries    are    searched    in    ${pre-
              fix}/lib/python   and   ${exec_prefix}/lib/python, 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 ${prefix}:${exec_prefix}.

       PYTHONPATH
              Augments the default search path for module files.  The  format
              is  the  same  as  the  shell's  $PATH:  one  or more directory
              pathnames separated by colons.   Non-existant  directories  are
              silently  ignored.   The  default  search  path is installation
              dependent, but generally begins with  ${prefix}/lib/python  (see  PYTHONHOME  above).   The  default  search path is
              always appended to $PYTHONPATH.  If a script argument is given,
              the  directory 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 .

       PYTHONSTARTUP
              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
              interactive session.  You can also change the  prompts  sys.ps1
              and sys.ps2 in this file.

       PYTHONY2K
              Set  this  to  a  non-empty  string to cause the time module to
              require dates specified as strings to  include  4-digit  years,
              otherwise  2-digit years are converted based on rules described
              in the time module documentation.

       PYTHONOPTIMIZE
              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.

       PYTHONDEBUG
              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.

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

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

       PYTHONVERBOSE
              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.

AUTHOR
       Guido van Rossum

       E-mail: guido@python.org

       And a cast of thousands.

INTERNET RESOURCES
       Main website:  http://www.python.org/
       Documentation:  http://www.python.org/doc/
       Community website:  http://starship.python.net/
       Developer resources:  http://sourceforge.net/project/python/
       FTP:  ftp://ftp.python.org/pub/python/
       Module repository:  http://www.vex.net/parnassus/
       Newsgroups:  comp.lang.python, comp.lang.python.announce

LICENSING
       Python is distributed under an Open  Source  license.   See  the  file
       "LICENSE" in the Python source distribution for information on terms &
       conditions for accessing and otherwise using Python  and  for  a  DIS-
       CLAIMER OF ALL WARRANTIES.



                         $Date: 2003/05/26 05:15:35 $               PYTHON(1)