Code Ghar (python کے بارے میں تحاریر)

Package Python in a Snap

Hamza Sheikh — Tue, 09 Jan 2018 04:20:24 GMT

Getting newer versions of Python on long term support releases of Linux distributions, such as Ubuntu or CentOS, without interfering with the system Python can be pretty involved. Doing it on multiple instances is even harder. Fortunately, it is possible and quite easy by using snapd.

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How to Use Python Virtualenv

Hamza Sheikh — Wed, 01 Nov 2017 01:43:30 GMT

A Python virtualenv is an isolated directory that serves as the root filesystem (kind of) for an installation of Python. In simpler terms, Python is installed in a non-privileged directory by a regular user. Anything installed for that instance of Python does not affect any other Python instance installed on the system.

This guide will show you how each instance of a Python interpreter differs from others and how to use this to your advantage.

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Use select() in Python Socket Programming at Your Own Risk

Hamza Sheikh — Fri, 07 Jul 2017 21:38:20 GMT

When one reads the Python Socket Programming HOWTO, non-blocking sockets are mentioned along with select. This is a tale of when select can cause issues if you're not careful.

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Essential pkgsrc - The Missing Mini Handbook

Hamza Sheikh — Sat, 25 Mar 2017 19:29:16 GMT

pkgsrc is a cross operating system package manager. It supports -- among many others -- NetBSD, Minix, SmartOS, Linux, and macOS. I like it because of this portability. It also has the additional, and I would say the best, benefit of being installed in the home directory and run completely without needing root access. I also like that I don't have to depend on binary packages built by someone else, say Joyent, although there's absolutely nothing wrong with it. Finally, it provides a large number of different packages. I have never encountered a package that I needed but was not available. In short pkgsrc is a portable, featureful, and flexible package manager. What's not to like?

pkgsrc can sometimes be a little behind native package managers, such as MacPorts on macOS, but it catches up quickly. For my use case -- getting access to multiple versions of Python -- it works well enough if I closely follow its trunk branch.

There's generally good and detailed documentation available for pkgsrc but an introductory guide that pulled in some essential starter information was lacking. This guide fills that void by making it easy to get started with pkgsrc and learn about some of its core concepts. Thus, I dubbed it the mini handbook or the missing starter handbook.

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Install Latest Python on CentOS 7

Hamza Sheikh — Wed, 13 Apr 2016 05:07:07 GMT

There are many options to install newer Python on CentOS, including building from source, installing from EPEL, installing from Software Collections (SCL), installing third party rpm package, etc. These all work to some degree of success. I had a different use case and could not find a pre-built rpm package to fit it.

My use case had these restraints:

Install newer Python alongside the default system version
Install multiple Python versions simultaneously
Install the latest release from upstream Python project not just the latest release from a repository (repo)
Do not build from source unless absolutely necessary

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Python readline Bug

Hamza Sheikh — Tue, 06 Oct 2015 22:23:12 GMT

Problem

In the Python interpreter whenever I hit enter it would show a blank line without a prompt and I'd have to press enter again to see the prompt. When I exited the interpreter the terminal would not show anything I typed. Pressing the return key would show my shell prompt on the same line. Up arrow or down arrow keys did not make any difference. reset was a last resort.

For example,

Python 3.4.3 (default, Aug 26 2015, 18:29:14)
[GCC 4.2.1 Compatible Apple LLVM 6.0 (clang-600.0.56)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> abs(1-0)
>>> 1

>>> ^D>>>
~ $ ~ $ ~ $ reset

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Echo Server and Client with Twisted

Hamza Sheikh — Wed, 11 Feb 2015 00:59:32 GMT

Echo Server and Client with Twisted

This is an introduction to Twisted using an echo server and client as an example.

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Install Python from Source in Linux

Hamza Sheikh — Wed, 11 Feb 2015 00:36:10 GMT

Install Python from Source in Linux

This guide is for when you need to install a Python release different from what comes with your distribution in the repos. We'll install it to our home directory. This guide was tested to be working on Ubuntu 14.04.

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Setup New Python Project with pyscaffold

Hamza Sheikh — Tue, 28 Oct 2014 04:10:01 GMT

Setup New Python Project with pyscaffold

This guide shows you how to setup a new Python project. This package can then be uploaded to PyPI to make it available to everyone.

The examples used in this guide were run and tested on Ubuntu 14.04 with Python 3.4.0. If you're using a different platform you may have to tweak the instructions accordingly.

This guide was possible thanks to How to Setup a new Python Project.

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Install Nikola in virtualenv

Hamza Sheikh — Tue, 14 Oct 2014 17:01:36 GMT

Nikola is a static website/blog generator written in Python. You can install it in a virtualenv. Although it supports Python 2 and Python 3 I had trouble using Nikola version 7.1 with Python 3.4. Python 2.7 (tested on Ubuntu 14.04) and Python 3.3 (tested on Mac OS X Mavericks) worked fine.

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Create Sequence Diagrams Using seqdiag

Hamza Sheikh — Wed, 01 Oct 2014 18:06:44 GMT

Have you ever needed to create sequence diagrams? If you're like me you constantly have to. Up to now I have always used a manual process using pen/paper or Visio. But I wanted an easier way and found seqdiag.

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SaltStack Quickstart Guide on Mac OS X

Hamza Sheikh — Sun, 03 Aug 2014 21:32:20 GMT

As always, refer to the official SaltStack documentation first.

To get up and running with SaltStack on Mac OS X can be a daunting task. I have found it much easier to use MacPorts to accomplish any such tasks.

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gevent Quickstart Guide

Hamza Sheikh — Fri, 01 Aug 2014 18:28:44 GMT

This is a simple list of steps on how to get started with installing gevent on openSUSE (tested on openSUSE 13.1 with gevent 1.0.1). We'll use virtualenv instead of a system-wide install.

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