Use Python For Vm Management

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Use Python for easy VM management
The popularity of Python continues to grow, as different use cases are recognized and new features are added. You may follow this article to manage VMs with the simple programming language (Python).
In this era of DevOps, companies expect system administrators to have some knowledge of programming. If you don't, you should consider learning. An administrator who can write code is much more valuable and productive than someone who can't.
Why use Python?
To put it very simple: Python is easy to use.
Python is one of the most widely used programming languages and easy to learn. And like JavaScript, it's a very old programming language that's rising in popularity, as engineers keep finding new uses for it and keep adding new features.
Many of thesellers support some kind of Python interface for their product. And if they don't, then they back representational state transfer, which Python can do, as well. Whatever you can do with Curl, you can do the same with Python.
Python is a highly interpreted language. This means, even though you can compile it, there’s no need to do so. It interprets code one line at a time. Once you run the shell, it works as a read-evaluate-print-loop interactive interpreter. It responds immediately when you type commands, which is the simplest way to write code.
The other reason to use Python is there's a huge repository of free APIs one can use to interact with everything, from OpenStack to Amazon Web Services (AWS) to Twitter.
Skills needed to use Python
To use Python, you need logical reasoning and understand mathematics, as all programming languages are built on those. Also, you need to understand abstract concepts like logic; data structures (DS), lists and arrays. At least, you need to understand what integers, decimals and character strings are.
What resources are there?
If you have the time and are comfortable learninghow to program through reading manuals and doing tutorials, you probably might not need to take a class to learn Python.
In many cases, you don't need to write original code to do many tasks, as someone has already done it. Just search the web, copy the code and change it to fit what you are doing, unless it has a copyright.
You will also find a list of learning resources on the official Python website.
Installing Python
One challenging characteristic of Python is Linux distributions ship with Python version 2, which is reaching the end. However, some Linux utilities require Python 2, and changing to version 3 might affect your system. Using Python 3 will ensure your code works in the future, but be sure you concur the consequences of upgrading.
This dual-version system can sometimes causeupsetting bugs if you get the two environments mixed up. Dependent on which version of Python and pip -- used to install Python APIs -- you're using, they can be put in two different places:
ls -d /usr/bin/python*
/usr/bin/python /usr/bin/python2-config /usr/bin/python3m
/usr/bin/python2 /usr/bin/python3 /usr/bin/python-config
/usr/bin/python2.7 /usr/bin/python3.5
/usr/bin/python2.7-config /usr/bin/python3.5m
There are several ways to this problem, one such is setting the environment variable to PYTHONPATH. And you can type pip3 and python3 when you want to use version 3.
With Ubuntu 16+, you possibly won't have any issues, but you might with CentOS 6.8 and earlier versions.
Some simple Python examples
Python is not a typed language; this implies that when you use Python, you can give a variable a value without declaring its type. This makes programming really simple.
In the instance given below, "a" is an integer. In the first line, ‘I’ define the value of "a" In the second line, ‘I’ request the value of "a" and the systems responds with the value ‘I’ set in the earlier line.
>>> a = 2
>>> a
2
See how to declare a function below. The key thing to note here is four blank spaces specify the indentation level. So, don't use brackets or a semicolon.
>>>def twice(a):
... return a * 2
...
>>> twice(a)
4
We can see above that we made "a" equal two. Then, in the function twice, we define that the function must be double the value sent of the integer. There, we also use the letter "a" as the symbol for the parameter passed into the function. Here you need to understand one programming concept called scope. The "a" within the function isn't the same as "a" outside the function. If you aren't aware of scope, you could spend all day trying to find a bug in your code.
Earlier, we spoke of the power of frameworks. For example, in order to interact with the OS, you can simply write:
importos
You can then take other actions, such as list the directory contents:
os.listdir("/tmp")
Or, you canalso use a variable to define a new command:
>>>dir = "/tmp"
>>>os.listdir(dir)
Python supports objects, but you won't need to use them for most of the tasks. Python has a lot of features that a learner would find complex, like inline functions called lambda and dictionaryobjects, which are key-value pairs.
When you use Python, start simple and build your skill over time. You will find editors for Python code that will help you catch errors at code time versus runtime, which is far easier than using vi and Bash. And the interactive Python shell is one of the best ways to write code, as you can get one small paragraph working at a time.

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