Sponsored Content
Top Forums Shell Programming and Scripting **python : passing list as argument and updating in definition Post 302952013 by Aia on Wednesday 12th of August 2015 01:41:01 PM
Old 08-12-2015
In Python the assignment operator `=' never copies data. Whatever is at the left of the `=' is a binding label to a value, not a variable per se. This is significant, since moving labels do not produce another variable.

I recommend you watch Ned Batchelder - Facts and Myths about Python names and values - PyCon 2015 if you are interested on it.
At 15:50 you'll get presentation related to your query, but I would watch it from the beginning since the concept of binding and rebinding labels builds from understanding mutable and immutable values.

Hope it helps.
 

10 More Discussions You Might Find Interesting

1. Programming

Thread Argument Passing

#include <stdio.h> #include <pthread.h> #define NUM_THREADS 4 /* function to be executed by the new thread*/ void *PrintHello(void * threadid) { printf("\n %3d:Hello World!\n",threadid); pthread_exit(NULL); } int main(int argc, char * argv) { int *taskids; int... (2 Replies)
Discussion started by: narom
2 Replies

2. Shell Programming and Scripting

Problem with Argument Passing

Greetings, I am wrapping the monitoring commands like vmstat, sar, iostat and call via arguments I want ./unix_stats.sh -v vmstat -p <SEC> -d <Duration> to give vmstat values, and similarly iostat etc.,. Also if I give ./unix_stats.sh -v vmstat -i iostat -p <SEC> -d <Duration> should give... (4 Replies)
Discussion started by: A_Rod
4 Replies

3. Shell Programming and Scripting

passing Argument

Hi All, i have script like below.. echo "1) first option" echo "" echo "2) second option" echo "" echo "*) please enter the correct option" read select case $select in 1) echo "first option selected" ;; 2) echo "second option selected" ;; *) echo "please enter the correct... (4 Replies)
Discussion started by: Shahul
4 Replies

4. Shell Programming and Scripting

Recursive argument passing

I'm writing a script that can be called on itself, and must be able to pass arguments down to itself properly. The regular usage of the script is as follows: myfun cmd1 'options1' cmd2 'options2' input If you're interested, the nuts and bolts of this function simply compare the outputs of... (2 Replies)
Discussion started by: Sunlis
2 Replies

5. Shell Programming and Scripting

passing either of argument, not both in shell

Hi, I have a requirement to work on script, it should take either of arguments. wrote it as below. #!/bin/bash usage() { echo "$0: missing argument OR invalid option ! Usage : $0 -m|-r|-d } while getopts mrdvh opt; do case "$opt" in m) monitor_flag=monitor;;... (1 Reply)
Discussion started by: ramanaraoeee
1 Replies

6. Shell Programming and Scripting

passing an option as an argument!

Hi Folks I have got to the point where I can specify the arguments but how to pass an option is still mystery to me. Example: temp.csh a b c d set temp1 = $argv set temp2 = $argv set temp3 = $argv echo $temp1 a echo $temp2 b echo $temp3 c d I WANT: temp.csh a b c d -S 1 set temp1... (2 Replies)
Discussion started by: dixits
2 Replies

7. Shell Programming and Scripting

Help with passing argument

Hi, I have a script that is scheduled with cron and runs every night. The cron part looks like this: 00 20 * * 0,1,2,3,4,5,6 /usr/local/bin/BACKUP TBTARM HOT DELETE My issue is with the 3rd parameter. Somewhere in the script, i want to tell the script to delete some files if the 3rd... (7 Replies)
Discussion started by: dollypee
7 Replies

8. Shell Programming and Scripting

Argument passing

How to pass the alphabet character as a argument in case and in if block? ex: c=$1 if a-z ]] then echo "alphabet" case $1 in a-z) echo "the value is a alphabet" edit by bakunin: please use CODE-tags. We REALLY mean it. (9 Replies)
Discussion started by: Roozo
9 Replies

9. Programming

Python passing filename through argument

Hello, A python beginner question on passing filename thru argument. My code is: #!/usr/bin/python import sys, getopt import os def main(argv): try: opts, args = getopt.getopt(sys.argv,"hi:o:ce", ) except getopt.GetoptError: usage() print("Usage: %s... (6 Replies)
Discussion started by: yifangt
6 Replies

10. UNIX for Beginners Questions & Answers

Passing a second argument

I am trying to pass a second argument like so: if ] then export ARG2=$2 else message "Second argument not specified: USAGE - $PROGRAM_NAME ARG1 ARG2" checkerror -e 2 -m "Please specify if it is a history or weekly (H or W) extract in the 2nd argument" fi however, it always goes... (4 Replies)
Discussion started by: MIA651
4 Replies
PYTHON(1)						    BSD General Commands Manual 						 PYTHON(1)

NAME
python, pythonw -- an interpreted, interactive, object-oriented programming language SYNOPSIS
python ... pythonw ... DESCRIPTION
To support multiple versions, the programs named python and pythonw now just select the real version of Python to run, depending on various settings. (As of Python 2.5, python and pythonw are interchangeable; both execute Python in the context of an application bundle, which means they have access to the Graphical User Interface; thus both can, when properly programmed, display windows, dialogs, etc.) The current supported versions are 2.6 and 2.7, with the default being 2.6. Use % man python2.6 % man python2.7 % man pythonw2.6 % man pythonw2.7 to see the man page for a specific version. Without a version specified, % man pydoc and the like, will show the man page for the (unmodified) default version of Python (2.6). To see the man page for a specific version, use, for example, % man pydoc2.7 CHANGING THE DEFAULT PYTHON
Using % defaults write com.apple.versioner.python Version 2.7 will make version 2.7 the user default when running the both the python and pythonw commands (versioner is the internal name of the version- selection software used). To set a system-wide default, replace 'com.apple.versioner.python' with '/Library/Preferences/com.apple.versioner.python' (admin privileges will be required). The environment variable VERSIONER_PYTHON_VERSION can also be used to set the python and pythonw version: % export VERSIONER_PYTHON_VERSION=2.7 # Bourne-like shells or % setenv VERSIONER_PYTHON_VERSION 2.7 # C-like shells % python ... This environment variable takes precedence over the preference file settings. 64-BIT SUPPORT Versions 2.6 and 2.7 support 64-bit execution (which is on by default). Like the version of Python, the python command can select between 32 and 64-bit execution (when both are available). Use: % defaults write com.apple.versioner.python Prefer-32-Bit -bool yes to make 32-bit execution the user default (using '/Library/Preferences/com.apple.versioner.python' will set the system-wide default). The environment variable VERSIONER_PYTHON_PREFER_32_BIT can also be used (has precedence over the preference file): % export VERSIONER_PYTHON_PREFER_32_BIT=yes # Bourne-like shells or % setenv VERSIONER_PYTHON_PREFER_32_BIT yes # C-like shells Again, the preference setting and environmental variable applies to both python and pythonw. USING A SPECIFIC VERSION
Rather than using the python command, one can use a specific version directly. For example, running python2.7 from the command line will run the 2.7 version of Python, independent of what the default version of Python is. One can use a specific version of Python on the #! line of a script, but that may have portability and future compatibility issues. Note that the preference files and environment variable that apply to the python command, do not apply when running a specific version of Python. In particular, running python2.6 will always default to 64-bit execution (unless one uses the arch(1) command to specifically select a 32-bit architecture). SEE ALSO
python2.6(1), python2.7(1), pythonw2.6(1), pythonw2.7(1), arch(1) BSD
Aug 10, 2008 BSD
All times are GMT -4. The time now is 08:58 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy