Python-Teaching: Difference between revisions

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<pre  class="gcommand">
<pre  class="gcommand">
ml Python/3.10.4-GCCcore-11.3.0
ml Python/3.12.3-GCCcore-13.3.0
python -h
python -h


usage: python [option] ... [-c cmd | -m mod | file | -] [arg] ...
usage: python [option] ... [-c cmd | -m mod | file | -] [arg] ...
Options and arguments (and corresponding environment variables):
Options (and corresponding environment variables):
-b    : issue warnings about str(bytes_instance), str(bytearray_instance)
-b    : issue warnings about converting bytes/bytearray to str and comparing
         and comparing bytes/bytearray with str. (-bb: issue errors)
         bytes/bytearray with str or bytes with int. (-bb: issue errors)
-B    : don't write .pyc files on import; also PYTHONDONTWRITEBYTECODE=x
-B    : don't write .pyc files on import; also PYTHONDONTWRITEBYTECODE=x
-c cmd : program passed in as string (terminates option list)
-c cmd : program passed in as string (terminates option list)
Line 92: Line 92:
         debug builds); also PYTHONDEBUG=x
         debug builds); also PYTHONDEBUG=x
-E    : ignore PYTHON* environment variables (such as PYTHONPATH)
-E    : ignore PYTHON* environment variables (such as PYTHONPATH)
-h    : print this help message and exit (also --help)
-h    : print this help message and exit (also -? or --help)
-i    : inspect interactively after running script; forces a prompt even
-i    : inspect interactively after running script; forces a prompt even
         if stdin does not appear to be a terminal; also PYTHONINSPECT=x
         if stdin does not appear to be a terminal; also PYTHONINSPECT=x
Line 101: Line 101:
-OO    : do -O changes and also discard docstrings; add .opt-2 before
-OO    : do -O changes and also discard docstrings; add .opt-2 before
         .pyc extension
         .pyc extension
-P    : don't prepend a potentially unsafe path to sys.path; also
        PYTHONSAFEPATH
-q    : don't print version and copyright messages on interactive startup
-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 add user site directory to sys.path; also PYTHONNOUSERSITE=x
-S    : don't imply 'import site' on initialization
-S    : don't imply 'import site' on initialization
-u    : force the stdout and stderr streams to be unbuffered;
-u    : force the stdout and stderr streams to be unbuffered;
Line 113: Line 115:
         also PYTHONWARNINGS=arg
         also PYTHONWARNINGS=arg
-x    : skip first line of source, allowing use of non-Unix forms of #!cmd
-x    : skip first line of source, allowing use of non-Unix forms of #!cmd
-X opt : set implementation-specific option. The following options are available:
-X opt : set implementation-specific option
 
--check-hash-based-pycs always|default|never:
        -X faulthandler: enable faulthandler
         control how Python invalidates hash-based .pyc files
         -X showrefcount: output the total reference count and number of used
--help-env: print help about Python environment variables and exit
            memory blocks when the program finishes or after each statement in the
--help-xoptions: print help about implementation-specific -X options and exit
            interactive interpreter. This only works on debug builds
--help-all: print complete help information and exit
        -X tracemalloc: start tracing Python memory allocations using the
            tracemalloc module. By default, only the most recent frame is stored in a
            traceback of a trace. Use -X tracemalloc=NFRAME to start tracing with a
            traceback limit of NFRAME frames
        -X importtime: show how long each import takes. It shows module name,
            cumulative time (including nested imports) and self time (excluding
            nested imports). Note that its output may be broken in multi-threaded
            application. Typical usage is python3 -X importtime -c 'import asyncio'
        -X dev: enable CPython's "development mode", introducing additional runtime
            checks which are too expensive to be enabled by default. Effect of the
            developer mode:
                * Add default warning filter, as -W default
                * Install debug hooks on memory allocators: see the PyMem_SetupDebugHooks() C function
                * Enable the faulthandler module to dump the Python traceback on a crash
                * Enable asyncio debug mode
                * Set the dev_mode attribute of sys.flags to True
                * io.IOBase destructor logs close() exceptions
        -X utf8: enable UTF-8 mode for operating system interfaces, overriding the default
            locale-aware mode. -X utf8=0 explicitly disables UTF-8 mode (even when it would
            otherwise activate automatically)
        -X pycache_prefix=PATH: enable writing .pyc files to a parallel tree rooted at the
            given directory instead of to the code tree
        -X warn_default_encoding: enable opt-in EncodingWarning for 'encoding=None'


--check-hash-based-pycs always|default|never:
Arguments:
    control how Python invalidates hash-based .pyc files
file  : program read from script file
file  : program read from script file
-      : program read from stdin (default; interactive mode if a tty)
-      : program read from stdin (default; interactive mode if a tty)
arg ...: arguments passed to program in sys.argv[1:]
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/pythonX.X.
PYTHONPLATLIBDIR : override sys.platlibdir.
PYTHONCASEOK : ignore case in 'import' statements (Windows).
PYTHONUTF8: if set to 1, enable the UTF-8 mode.
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 and bytes 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.
PYTHONCOERCECLOCALE: if this variable is set to 0, it disables the locale
  coercion behavior. Use PYTHONCOERCECLOCALE=warn to request display of
  locale coercion and locale compatibility warnings on stderr.
PYTHONBREAKPOINT: if this variable is set to 0, it disables the default
  debugger. It can be set to the callable of your debugger of choice.
PYTHONDEVMODE: enable the development mode.
PYTHONPYCACHEPREFIX: root directory for bytecode cache (pyc) files.
PYTHONWARNDEFAULTENCODING: enable opt-in EncodingWarning for 'encoding=None'.


</pre>
</pre>

Latest revision as of 15:16, 9 January 2026

Category

Programming

Program On

Teaching

Version

2.7.18, 3.9.6, 3.10.4, 3.10.8, 3.11.3, 3.11.5, 3.12.3, 3.13.1, 3.13.5

Author / Distributor

Python

Description

"Python is a programming language that lets you work more quickly and integrate your systems more effectively." More details are at Python

Running Program

Please also see Python-Sapelo2 as that documentation applies to the teaching cluster as well.

To see all versions of Python installed on the cluster, use: 

ml spider Python

For example:

Version 2.7.18

Installed in /apps/eb/Python/2.7.18-GCCcore-11.3.0

To use this version, please load the module with 

ml Python/2.7.18-GCCcore-11.3.0

Version 3.12.3

Installed in /apps/eb/Python/3.12.3-GCCcore-13.3.0

To use this version, please load the module with 

ml Python/3.12.3-GCCcore-13.3.0


Here is an example of a shell script, sub.sh, to run on the batch queue:

#!/bin/bash
#SBATCH --job-name=j_Python
#SBATCH --partition=batch
#SBATCH --mail-type=ALL
#SBATCH --mail-user=username@uga.edu
#SBATCH --ntasks=1
#SBATCH --mem=10gb
#SBATCH --time=08:00:00
#SBATCH --output=Python.%j.out
#SBATCH --error=Python.%j.err

cd $SLURM_SUBMIT_DIR
ml Python/3.12.3-GCCcore-13.3.0
python [options]

In the real submission script, at least all the above underlined values need to be reviewed or to be replaced by the proper values.

Please refer to Running_Jobs_on_the_teaching_cluster, Run X window Jobs and Run interactive Jobs for more details of running jobs at Teaching cluster.


Here is an example of job submission command: 

sbatch ./sub.sh

Documentation

ml Python/3.12.3-GCCcore-13.3.0
python -h

usage: python [option] ... [-c cmd | -m mod | file | -] [arg] ...
Options (and corresponding environment variables):
-b     : issue warnings about converting bytes/bytearray to str and comparing
         bytes/bytearray with str or bytes with int. (-bb: issue errors)
-B     : don't write .pyc files on import; also PYTHONDONTWRITEBYTECODE=x
-c cmd : program passed in as string (terminates option list)
-d     : turn on parser debugging output (for experts only, only works on
         debug builds); also PYTHONDEBUG=x
-E     : ignore PYTHON* environment variables (such as PYTHONPATH)
-h     : print this help message and exit (also -? or --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     : remove assert and __debug__-dependent statements; add .opt-1 before
         .pyc extension; also PYTHONOPTIMIZE=x
-OO    : do -O changes and also discard docstrings; add .opt-2 before
         .pyc extension
-P     : don't prepend a potentially unsafe path to sys.path; also
         PYTHONSAFEPATH
-q     : don't print version and copyright messages on interactive startup
-s     : don't add user site directory to sys.path; also PYTHONNOUSERSITE=x
-S     : don't imply 'import site' on initialization
-u     : force the stdout and stderr streams to be unbuffered;
         this option has no effect on stdin; also PYTHONUNBUFFERED=x
-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
--check-hash-based-pycs always|default|never:
         control how Python invalidates hash-based .pyc files
--help-env: print help about Python environment variables and exit
--help-xoptions: print help about implementation-specific -X options and exit
--help-all: print complete help information and exit

Arguments:
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:]

Back to Top

Installation

Source code is obtained from Python

System

64-bit Linux

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