Programming First Steps: Java or Python?

I am posting this as an extended response to the quesiton that a medic friend of mine asked me the other day. The main question was whether learning Java or Python was best for getting “a basic understanding of coding (medically related)” and “which one will serve best in the future within a remit of medical apps“.

The short answers is that it depends… and my answer is not only valid for medical applications, but in general. I believe that both are very good popular programming languages. Learning the basics of programming can be done in any programming language of your choice, including both Python and Java. If the aim is to get to grips with what programming is all about even getting to learn a bit of Scratch or Blocky could be a good start. I recommend looking as well at Swift Playgrounds. They all will let you have a look at the basics of programming and will get you started in an easy way.

In this case the query is mor nuance and the answer is also “it depends”. For example are there any other people around you who are already using a particualr programming language for their medical (or any other area of knowledge) application? For example, when doing a PhD I recommend you look at what other candidates are using for their work and stick to it. The reason for this is that if you have any questions there are people around you that may be able to support you. Also you may end up working with them and programming in the same language helps. In this case, if there are a number of medics that are already getting their hands dirty with one particular programming language I’d say go for that. And notice that it does not have to be neither Java nor Python.

In short you can’t go wrong with picking one of them to start with. Once you start, you may pick up the other with less trepidation.

If you are stuck, I would probably recommend using Python, but then again I may be biased. After all, I have written a couple of books for pythonistas, ok, ok I have also written one for Matlab. That is also an excellent language although not open source. In that case take a look at Octave… but I digress.

In the rest of the post I will look at some of the similarities and differences between Python and Java in the hope this may help you decide.

Learning curve

The learning curve for Java and Python is very diffterent. I believe that Python is a much easier language to get started. However, once you have picked up the basics in any of them you can contribute to production level code quite easily. Both languages are object oriented and depending on your level of knowledge you may be able to read through a program an figure out what it is doing.

The learning curve for anything depends on what you already know, how interested you are in learning the topic, and the learning environment. For example, if you have already done some type of coding or scripting, even if it is pasting some JavaScript into a web page, you may be familiar with the code structure you will run into with a language like Java. Here is an example of Java code. Let us look at a Hello World program in Java:

class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, World!"); 
    }
}

What about Python? Well take a look:

print("Hello, world!")

Readability is part of the philosophy of writing Python code and we can see that in the example above. In this way, if you have never programmed before, Python tends to be easier to read.

Syntax

Syntax refers to the rules that we need to follow to write correct “sentences” in the language. Java’s syntax requires a bit more effort than Python’s. Let us take a look. The following program calculates the averge of some a collection of numbers in Java

public class Average {
    public static void main(String args[]){
       int i,total;
       int a[] = {0,6,9,2,7};
       int n = 5;
       total = 0;
 ​
       for(i=0; i<n; i++) {
          total += a[i];
      }
       System.out.println("Average :"+ total/(float)n);
    }
 
  • Curly braces define the blocks of code.
  • Each statement must end in a semicolon (;)
  • Each time you create a new variable, it must have a type. When we instantiate the i and total objects we define them as int and later on casted the value of n as a float to be able to obtain a decimal number
  • Formatting and spacing is not important. Although the code above looks nice, the programme will run even if all of it were in a single line (don’t do that…)(
  • You will also notice how verbose the code is. You will usually end up typing more writing Java code than you would with Python code.

In Python we can calculate the average with something like this:

def average(a):
   avg = sum(a)/len(a)
   return avg
   
 a = [0,6,9,2,7]
 avg = average(a)
 print("Average : {0}".format(avg))
  • Line breaks and indentation define blocks of code in Python. There are no extra symbols like semicolons at the end of a line
  • Python uses a colon to start classes, methods, and loops. You see that in the definition of average
  • Whitespace is important to Python. Developers use it to define blocks of code, so the lines in the code above could not run on one line.

Executing code

A big difference between Java and Python is how both languages execute code. Java is a compiled language and this means that the code needs to be “translated” so that the machine can run it. Python is an interpreted language and this means that the code is executed line by line without the need for compilation.

If you are interested in performance, the distinction above means that Python could be a bit slower that Java, but I think that for the type of programming you may start with this does not matter all that much.

In a nutshell

If you are interested in learning more about programming, either of them should be able to get you started. There may be a number of pros and cones to each languaage and I would recommend you ask colleagues what they are using for the type os applications you are interested in. All in all it does not matter which one you chose. My recommendation is to stick with your choice and in no time you will pick up the nunances and idiosyncrasies of the language.


Also published on Medium.

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