Python is a general-purpose programming language, it means that it can be used to build just about anything, which will be made easy with the right tools and libraries. The article states all the key features of the Python programming language that a programmer must-know!
Python Shell: Without a doubt, one of the most useful features of Python is that it comes auto-installed with its own shell. The Python Shell can be executed by typing in from the command line. By doing so, we will see the default version number. The three arrows asking for our input. If we have multiple versions of Python installed, we may need to add in the version number to get the correct version.
Python shell is so useful to know because it allows us to test out simple commands in isolation to detect if there’s something going to be a syntax or logical error, therefore In this way, Python shells help us to avoid consuming much more time as well as memory spaces.
Different Versions of Python: It is very important for a Python Programmer to know which version of python they are working on as that changes many things out there. Python programming language versions are usually numbered as ABC. For example, going from 2.7.3 to 2.7.4 means that the Python made some minor bug fixes while going from 2.xx to 3.xx represents a major change that took place between the two versions. Note the ‘x’ here, which is intentional; if a Python feature can apply to version number 2.7.C for any valid ‘C’ value, then we put in an ‘x’ and refer to Python 2.7.x. We can also omit the ‘x’ entirely and just use 2.7.
Python has a stable and commonly used version 3.8. Less important is the third character. Currently, 3.8.2 is the current version, which was released on May 13, 2020. Here both the older version 2.7 and 3.8 are perfectly fine to use, but 3.8 is the future of the language and someone who just starting his/her learning Python today should probably use Python 3.8 over 2.7.
Using ‘os’ and ‘sys’: The os and sys modules are incredibly useful for a python programmer just for the purposes of convenience and generality. Firstly, let’s discuss the sys module. The biggest advantage possibly that it offers to the programmer is the use of command-line inputs to the program. Say we have built a large program that will perform some task that depends on inputs from the user.
In machine learning, We implemented the k-means clustering algorithm. This is a learning algorithm that is given data and can classify it into groups depending on how many clusters are given as input. It’s clear that this can be useful in many real-life applications. Someone who has standardized data on medical patients’ records (e.g. blood-sugar levels, height, weight, etc.) may want to classify patients into two “clusters,” which could be (1) healthy or (2) ill, or perhaps there could be ‘n’ clusters, where patients classified into lower-numbered clusters have a better outlook than those with high numbers.
To perform k-means clustering, then, we logically need two inputs: (1) the data itself and (2) the number of clusters. One idea is to put these directly into the program, and then run it. But what happens if we want to keep changing the data file we’re using or the number of clusters? Each time the program has finished executing, we’d have to go back into our text editor and modify it before re-executing it.
A better way would be to use command line arguments. Changing inputs on the command line is usually faster than opening a text editor and retyping the variables. We can do this with sys.argv, which takes in input from the command line. As an extra protection, one can also make sure that the user inputs the correct number of parameters. Another better way is to make other Python script and use os.system to call kmeans_clustering as many times as we want. And this is as easy as changing the input to os.system.
So now the required program will call kmeans_clustering 99 times automatically, each time with a different parameter for the number of clusters. Therefore it is very useful, as this is one of the biggest benefits of using a program to call another program. We have to just worry that if we make a change to a program while another script is calling it, then those changes will be reflected the next time the program gets called.
Classes and Functions: In Python It is very easy to define a function, using def, Recursive functions are also straightforward, and behave as in most major object-oriented programming languages. Compared to Java, we haven’t used too many classes in my Python Programs. But Still, classes are an important part of object-oriented languages and Python is object-oriented, so it’s worth it to read the Classes documentation if have the time.
Python classes provide all the standard features of Object-Oriented Programming: the class inheritance mechanism allows multiple base classes, a derived class can override any methods of its base class or classes and a method can call the method of a base class with the same name. Objects can contain arbitrary amounts and kinds of data. As is true for modules, classes partake of the dynamic nature of Python: they are created at runtime and can be modified further after creation.
File Management: It’s important to know the correct ways to incorporate files in one’s code. The official documentation explains that the open keyword is used for this purpose. It is very simple, and we can loop through the file to analyse it line by line. Alternatively, we can use the readlines () method to create a list consisting of each line in the file, but just be wary if the file is large. The f.close() is very important since it’s used to free up memory.
Dictionaries & Sets: When we talked in reference to the Python Programming Lists are by far the most common data structure we use, but we still make extensive use of dictionaries, sets and other data structures, since they have their own advantages.
A set is simply a container that holds items, like a list, but only holds distinct elements. That is, if you add in element X to a set already containing X, the set doesn’t change. This can be an advantage of sets over lists. Once a set is created, we cannot change its items but can add new items. Along with the Sets we have one more incredibly useful data structure that is Dictionary. A dictionary is something that associates to each key-value so it’s essentially a function that pairs up elements together.
Slicing: When we talked in reference to the Python Programming Lists are by far the most common data structure we use, but we still make extensive use of dictionaries, sets, and other data structures, since they have their own advantages. A set is simply a container that holds items, like a list, but only holds distinct elements. That is, if you add in element X to a set already containing X, the set doesn’t change. This can be an advantage of sets over lists. Once a set is created, we cannot change its items but can add new items.
Along with the Sets we have one more incredibly useful data structure that is Dictionary. A dictionary is something that associates to each key-value so it’s essentially a function that pairs up elements together.
Python Frameworks: Another important concept which we have to talk about is Frameworks. Python frameworks is very important but that does not mean that one has to know all of them. It is completely based on the project that we are trying to execute,We will be required to know the most important ones for that project, but the most popular ones that are used often are Flask, Django.
Front-End & Back-End Technologies: Front-end is what a user sees when visiting a page while the back-end is what happens behind the scenes. The back-end is where the programs are executed and queries data from the database to display it to the website. Python is one of the programming languages used in developing the back-end. However, a python developer is required to link with the front-end developers to link the client-side with the server-side. In this case, it is essential to understand how the front-end work and how the application will appear.
Indentation and No Braces: Unlike other programming languages like Java and C++, Python does not use braces to delimit code. One most important thing that a python programmer should keep in his mind while programming is Indentation. It is mandatory with Python. If we choose to import it from the future package, it gives us an unexpected error.
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By Mayank Mishra