Python vs. Java: Which Should I Learn?

Java and Python are two of the most popular programming languages. Of the two, Java is the faster language, 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 to consider.

In this article, we'll explore how Java and Python compare to one another, including what they are, their use cases, and their advantages and disadvantages. Afterward, if you're interested in learning either of these impactful programming languages, consider enrolling in either the University of Michigan's Python for Everybody Specialization or Duke University's Java Programming: Solving Problems with Software course.

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 sixth most commonly used programming language [1]. It's also the most popular programming language among developers, according to HackerRank [2]. Several factors are driving Java's continued popularity, primarily its platform independence and its relative ease to learn.

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 other 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.

Read more: Java vs. C++ Comparison: What Are the Differences in These Programming Languages?

Java use cases

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

Learn more about Java in the context of other programming languages in this lecture by Professor Robert Sedgewick from Princeton University's Computer Science: Programming with a Purpose course:

Advantages of Java

Speed and efficiency are two of the big draws of using Java. It's also one of the coding languages considered to be 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 practicing. Other advantages of using Java include the following:

• It's simple: The syntax is straightforward, making it easy to write. It's not as complex as languages like C++, and it 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 big project development. It also provides flexibility and easier troubleshooting, and the ability to reuse the code.

• It has a large global community: This is helpful when you're learning Java or should you run into any problems.

• It supports multithreading: When you use Java, you can run more than one thread at a time. 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 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 right programming language for you to start with, it’s essential to consider its weaknesses. One of the main downsides to using Java is that it uses a large amount of 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 during the process, other threads have to stop while the garbage collector works. 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 have the ability 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're creating 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 Statista, this general use, interpreted language is the third most popular coding language among developers worldwide [3]. Python's popularity has experienced explosive growth in the past few years, likely due to its ease-of-use for IoT devices, data science, and machine learning applications. Further, Python added over 8 million new developers to its community in the last two years, according to SlashData's “State of the Developer Nation” report [4].

Read more: What Can You Do as a Python Developer

What is Python?

Python has been around since 1991, when it was first released. The programming language was designed by Guido van Rossum 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 due to it boasting 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 use cases

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 among programmers for back-end development and app development. It's also a top choice for those working in data science and machine learning, 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 difficult 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 that “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 just need an interpreter designed for that platform.

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

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

• It offers a more flexible approach to programming: 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 of how concise it is and because it's dynamically typed [6]. Additionally, it has control capabilities and integration features that can make applications more productive.

Practice your Python skills independently with tutorials

Not ready to commit to a course or a boot camp yet? You can read step-by-step guides for troubleshooting Python basics like syntax, if-else statements, exceptions, and working with loops in Coursera's free programming tutorials.

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 use in 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 a bit 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 amount of memory Python uses for each object.

Want to start playing with Python? Hear how the University of Michigan's Python for Everybody Specialization gives you the tools to practice Python with just your web browser in this lecture by Professor Charles Severance:

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 if you choose one—but which is better as a start? That depends upon what you find most interesting and which language feels like a good match for your goals. If you're just 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, you should take your goals into account.

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

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

You’ve got many options for learning either or both of these popular programming languages, including bootcamps and certificate programs.

1. 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, although they can last anywhere 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 organizations. They are typically not self-paced, so make sure you have enough time in your schedule to commit to this type of learning program.

2. Certificate programs

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

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Start learning Python or Java today with Coursera

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 learn Python fundamentals from an industry leader in technology with Google's Crash Course on Python. This beginner-friendly course can be completed in just 26 hours and covers essential Python concepts like data structures, syntax, and object-oriented programming (OOP).

For a more comprehensive introduction to Python that earns you a certificate from the University of Michigan, consider enrolling in the Python for Everybody Specialization. By the end, you'll have learned to develop programs for cleaning, analyzing, and visualizing data.

If you're learning a programming language for the first time and want to start with Java, Duke University offers a Java Programming and Software Engineering Fundamentals Specialization that covers core programming concepts while focusing on Java and JavaScript.

If you already have some coding experience, you can get acquainted with Java in just 11 hours with LearnQuest's Introduction to Java. The course outlines basic Java syntax, data types, expressions, operators, and branching and looping statements. By the end, you'll be able to write simple Java code on your own.