Manual Pages for UNIX Darwin command on man python

PYTHON(1) PYTHON(1)

NAME

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

guage

SYNOPSIS

ppyytthhoonn [ -dd ] [ -EE ] [ -hh ] [ -ii ] [ -OO ]

[ -QQ argument ] [ -SS ] [ -tt ] [ -uu ]

[ -vv ] [ -VV ] [ -WW argument ] [ -xx ]

[ -cc command | script | - ] [ arguments ]

DESCRIPTION

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 IINNTTEERR-

NNEETT RREESSOOUURRCCEESS 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 ppyyddoocc program. CCOOMMMMAANNDD LLIINNEE OOPPTTIIOONNSS

-cc command

Specify the command to execute (see next section). This termi-

nates the option list (following options are passed as arguments to the command).

-dd Turn on parser debugging output (for wizards only, depending on

compilation options).

-EE Ignore environment variables like PYTHONPATH and PYTHONHOME that

modify the behavior of the interpreter.

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

-ii When a script is passed as first argument or the -cc 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.

-OO 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.

-QQ 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/fixdiv.py script.

-SS Disable the import of the module site and the site-dependent

manipulations of sys.path that it entails.

-tt 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.

-uu 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.

-vv 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.

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

-WW 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 -WW options

may be given; when a warning matches more than one option, the

action for the last matching option is performed. Invalid -WW

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-

ule. The simplest form of argument is one of the following action

strings (or a unique abbreviation): iiggnnoorree to ignore all warn-

ings; ddeeffaauulltt to explicitly request the default behavior (print-

ing each warning once per source line); aallll 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); mmoodduullee to print each warning only only the first time it occurs in each module; oonnccee to print each warning only the first time it occurs in the program; or eerrrroorr 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.

-xx 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! IINNTTEERRPPRREETTEERR IINNTTEERRFFAACCEE 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 -cc 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 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 -cc 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 conven-

tions; ${prefix} and ${execprefix} are installation-dependent and

should be interpreted as for GNU software; they may be the same. The default for both is /usr/local.

${execprefix}/bin/python

Recommended location of the interpreter.

${prefix}/lib/python

${execprefix}/lib/python

Recommended locations of the directories containing the standard modules.

${prefix}/include/python

${execprefix}/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 ${prefix}/lib/python
sion> and ${execprefix}/lib/python, where ${prefix}
and ${execprefix} are installation-dependent directories, both
defaulting to /usr/local. When $PYTHONHOME is set to a single
directory, its value replaces both ${prefix} and ${execprefix}.
To specify different values for these, set $PYTHONHOME to ${pre-
fix}:${execprefix}.
PYTHONPATH 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-existant directories are
silently ignored. The default search path is installation
dependent, but generally begins with ${prefix}/lib/python sion> (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 -OO option. If set to an integer, it is equivalent to
specifying -OO multiple times.
PYTHONDEBUG
If this is set to a non-empty string it is equivalent to speci-
fying the -dd option. If set to an integer, it is equivalent to
specifying -dd multiple times.
PYTHONINSPECT
If this is set to a non-empty string it is equivalent to speci-
fying the -ii option.
PYTHONUNBUFFERED
If this is set to a non-empty string it is equivalent to speci-
fying the -uu option.
PYTHONVERBOSE
If this is set to a non-empty string it is equivalent to speci-
fying the -vv option. If set to an integer, it is equivalent to
specifying -vv multiple times.
AUTHOR Guido van Rossum
E-mail: guido@python.org
And a cast of thousands. IINNTTEERRNNEETT RREESSOOUURRCCEESS
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
LLIICCEENNSSIINNGG 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)