Save Lono

I’m in the process of moving my mindset from static linear scripting to an object oriented one.  My goal is to solve problems with algorithms I create myself.  It’s a tough climb because I come from Systems Admin/Networking side of things and didn’t benefit from Computer Science theory and advanced mathematics.  I’m hoping to eventually move into a DevOps role where I can organically absorb from devs.  It would be great to be able to observe other approaches to problem solving.

The video above is a Google interview prep question from Youtube.  The interviewee solves it with C++, I provide my version in Python below.  Essentially, they are solved in a similar way.  Granted, it took me two weeks of stewing on it and the man above did it on the spot, but he’s a Software Engineer, so I feel pretty good!

The problem is to find pairs of integers that add to 8 from a list assumed to be in ascending order.  Negatives and doubles are possible.

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For several months Python mysql-connector has been broken when attempting a install from pip.  In truth I’ve only tried Python 3, CentOS 6/7 and Fedora 21; in fact, this could be a more wide spread.  The simple solution is to install an earlier version.  The purpose of this post is to be a quick reminder of which is the most recent working version!

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Python’s Fabric module is an easy and efficient way for task based automation.  I use it to automate the installation of VoIP phone systems on CentOS 6/7.  In a nut shell, Fabric executes shell commands over SSH.  It also can be used to automate local tasks.  The purpose of this article is to highlight the basic process of capturing Fabric exceptions(try/except) using a wrapper function called a decorator.  A few well placed decorators can save lot of time coding the same thing over and over(like capturing a specific error). 

Most of you in the know about Python/Fabric probably  will find my examples trivial, but I had to dig to find the Fabric exception environment variable.  I’m sure it’s somewhere on the Fabric site… but I gave up after 30 minutes.  So hopefully you will find this post useful either way!

If you need help installing Python3, pip3 and Fabric please refer to my previous post.

Goals of this Post:

• create a simple Fabric function that creates a directory
• create a Fabric exception
• create Decorator for adding exception handling

Lets start with a basic fabfile.py: 

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