Python vs. Java: Which Should I Learn?

Java and Python are two of the most popular programming languages. Java is the faster language of the two, but Python is simpler and easier to learn. Each is well-established, platform-independent, and part of a large, supportive community. But that is where the similarities end. When you’re considering Python versus Java, each language has different uses for different purposes, and each has pros and cons. 

Java: The faster path

When it comes to sheer speed, Java is a clear winner. According to Stack Overflow, this general-use, compiled language is the fifth most commonly used programming language [1]. It's also the third-most in-demand programming language that hiring managers look for when hiring candidates, according to HackerRank [2]. Several factors drive Java's continued popularity, primarily its platform independence and relative ease of learning.

What is Java?

Java is a programming language and platform that's been around since 1995. Since its release, it has become one of the most popular languages among web developers and coding professionals. It's a general-purpose, object-oriented language. Unlike Python, Java is a compiled language, which is one of the reasons that it’s your faster option.

When you program with compiled languages like Java, the coding gets directly converted to machine code. That lets the processor execute much more quickly and efficiently while giving you increased control over hardware aspects like CPU usage. Other examples of compiled languages include C and C++, Rust, Go, and Haskell.

Java is widely used in web development, big data, and Android app development. It has also gained traction in cloud development and the Internet of Things (IoT). Java is also helpful for working on enterprise-level web applications and microservices. Various organisations use Java to build their web applications, including those in health care, education, insurance, and even governmental departments. Some big names using Java today include NASA, Google, and Facebook.

Advantages of Java

Speed and efficiency are two of the big draws of using Java. It's also one of the coding languages that is considered easy to learn. Because many of the processes of this high-level language run automatically, you won't have to do an intense study of how everything works as much as you would with a low-level language. You should be able to master it relatively quickly depending on how much time you can devote to learning and practising. Other advantages of using Java include the following:

• It's simple: The syntax is straightforward and easy to write. It's not as complex as languages like C++ and uses automatic memory allocation.

• It’s platform-independent: You can use Java on multiple types of computers, including Windows, iOS, Unix, and Linux systems, as long as it has the Java Virtual Machine (JVM) platform.

• It’s object-oriented: Because you create classes containing data and functions and objects that belong to those classes, it offers a more intuitive approach for extensive project development. It also provides flexibility, easier troubleshooting, and the ability to reuse the code.

• It has an extensive global community, which is helpful when learning Java or encountering problems.

• It supports multithreading: When you use Java, you can run more than one thread simultaneously. When running multiple threads, they share a common memory area to increase efficiency and performance.

• It’s secure: Java avoids using explicit pointers, runs inside a virtual machine called a sandbox, uses a byte-code verifier to check for illegal code, and provides library-level safety along with Java security package and run-time security checks. 

Disadvantages of Java

Before deciding whether Java is the correct programming language for you, it’s essential to consider its weaknesses. One of the main downsides to using Java is that it uses much memory—considerably more than Python. 

Additionally, Java manages its memory through garbage collection, which happens once the application you’re working on no longer references the object. Java’s garbage collector clears it from memory, but other threads have to stop while the garbage collector works during the process. The step impacts the overall performance of the application. Other disadvantages include:

• It doesn’t offer control over garbage collection: As a programmer, you won’t be able to control garbage collection using functions like free() or delete().

• It has a lot of words: Although Java is simple, it does tend to have a lot of words in it, which will often leave you with complex, lengthy sentences and explanations.

• It doesn't have a native look when you use it for desktops: Java has multiple graphical user interface (GUI) builders, but they aren't the best if you create complex UI on a desktop. Java is weaker when you're using it for desktop versus mobile when it comes to user experience and user interface. While there are many GUI builders to choose from, you'll need to do a lot of research to find the right one for your project.

Python: The simple path

Although Java is faster, Python is more versatile, easier to read, and has a simpler syntax. According to Stack Overflow, this general use of interpreted language is the fourth most popular coding language [1].  It's also one of the most in-demand programming languages that hiring managers look for when hiring candidates, according to HackerRank, second only to JavaScript [2]. 

Python's popularity has experienced explosive growth in the past few years, with more than 11.3 million coders choosing to use it, mainly for IoT, data science, and machine learning applications, according to ZDNet [3]. Further, Python has had a 25 percent growth rate, adding 2.3 million developers to its community between Q3 2020 and Q3 2021, according to SlashData's “State of the Developer Nation” [4].

What is Python?

Python has been around since 1991 when it was first released. Guido van Rossum designed the programming language with a design philosophy focused on code readability. One of the driving forces behind Python is its simplicity and the ease with which many coders can learn the language. It's an interpreted language, which means the program gets run through interpreters on a line-by-line basis for each command's execution.

Learning the language and testing programs is faster and easier in Python compared to Java primarily because it boasts a more concise syntax. As you're entering lines, you enter them right into the terminal instead of having to compile the entire program before running it. Other examples of interpreted languages include Ruby, PHP, and JavaScript.

Python empowers developers to employ a variety of programming styles while they're creating programs. Because it's so flexible, you might use it not just for object-oriented programming but also for functional and reflective programming. 

It's popular amongst programmers for back-end development and app development. It's also a top choice for data science and machine learning professionals, primarily because of its extensive libraries, including Scikit-learn and Pandas. It's the programming language used to develop many of the leading digital platforms and tools we use today, including Google Search, iRobot machines, and YouTube.

Advantages of Python

Python’s versatility is challenging to match, and it's so flexible that it encourages experimentation. This keeps programmers from being pigeonholed into only building one type of application. You can learn just one language and use it to make new and different things. 

Computer Weekly calls Python the most versatile programming language, noting, “Although there might be a better solution for any given problem, Python will always get the job done well” [5]. Other advantages of Python include:

• It’s platform-independent: Like Java, you can use Python on various platforms, including macOS, Windows, and Linux. You’ll need an interpreter designed for that platform.

• It allows for fast development: Because Python is dynamically typed, it's quick and friendly for development. Additionally, it uses asynchronous code to tackle situations and challenges faster because each code unit runs separately.

• It offers extensive libraries: Its large library supports everyday tasks and commands. It also contains code that can be used for various purposes, from generating documentation to unit testing to CGI.

• It offers a more flexible programming approach: Python supports a variety of programming styles and has multiple paradigms. Not only is this optimal for programmers who enjoy flexibility, but it also makes it ideal for start-ups that might need to shift approaches abruptly.

• It's free and open-source: You can download Python without any cost, and because it's so easy to learn and boasts one of the largest and most active communities—you should be able to start writing code in mere minutes.

• It may boost productivity: NetGuru says that Python is more productive than Java because it's concise and dynamically typed [6]. Additionally, it has control capabilities and integration features that can make applications more productive.

Disadvantages of Python

While Python is arguably one of the easiest and fastest languages to learn, it’s also decidedly slower to execute because it’s a dynamically typed, interpreted language, executed line-by-line. Python does extra work while executing the code, making it less suitable for projects that depend on speed. However, if speed isn’t a sensitive issue, Python’s slower nature won’t likely be a problem. 

Other potential disadvantages include:

• It only executes one thread at a time: Python has a Global Interpreter Lock that only lets one thread execute at a time, so if you're working on a multi-threaded CPU-bound program, it'll likely be even slower. Using multiprocessing programs instead of multithreaded programs can be an effective workaround.

• It isn't mobile native: Python can be effectively and easily used for mobile purposes, but you'll need to put more effort into finding libraries that give you the necessary framework. Some examples include Kivy, which lets you use the same API to create mobile apps and software that you can run on Raspberry PI, Linux, and Windows.

• It uses a large amount of memory: If you're working on a project where many objects are active in RAM, this could present an issue for you. Switching to NumPy could be an effective workaround to reduce the memory Python uses for each object.

How to start learning 

Learn just one, or learn them both. Many programmers eventually learn multiple programming languages. To get started, you’ll be better off choosing one—but which is better? That depends upon what you find most interesting and which language is a good match for your goals. If you're beginning to learn how to code, you might want to start by learning Python because many people learn it faster. It's simple and more concise, while Java has more lines of complex code. 

Evaluate your goals

When opting for a starting point, consider your goals.

Java is popular among programmers interested in web development, big data, cloud development, and Android app development. 

Python is favoured by those working in back-end development, app development, data science, and machine learning. 

You have many options for learning either or both of these popular programming languages, including bootcamps and certificate programmes.

Coding bootcamps

When you sign up for a bootcamp, you can expect an intensive, immersive experience designed to get qualified to use the language quickly. According to Course Report, the average bootcamp lasts around 14 weeks, between six and 28 weeks [7]. You might opt for a language-specific bootcamp or one that teaches you relevant high-level skills like data science, web development, or user experience design. You might find online or in-person bootcamps from educational institutions or private organisations. 

Certificate programmes

Certificate programmes vary in length and purpose, and you’ll emerge having earned proof of mastery of the necessary skills you can use on your CV. This path affords another alternative to pursuing a degree that focuses on your chosen topic. You'll be able to develop skills and proficiency in the programming language to apply to the work world.

Online courses

Another option is to take online courses to become more familiar with Java or Python before committing to a more rigorous form of training. You can start with courses such as Java Programming and Software Engineering Fundamentals Specialisation offered by Duke University or Python for Everybody Specialisation through the University of Michigan.