Java to python converter

This is simple basic alpha version of Java to Python code converter. The main goal of this tool is to provide functionality to deal with converting custom Java code into equivalent Python code.

Example of java to python

Here mentioned few examples which is based on arrays, strings and some useful packages which is generally used in java programming language.

Java array to python list

Java Code

class MyArray
{
  public static void main(String[] args)
  {
        // Simple array of integer elements
    int[] a = new int[]{1,2,3,4,5};
        int[][] b = new int[][]{{1,2,3},{4,5,6}};
        int[] c = new int[10];
    System.out.println(a.length);
        System.out.println(b.length);
        System.out.println(c.length);
  }
}

Converted Python

class MyArray :
    @staticmethod
    def main( args) :
        # Simple array of integer elements
        a = [1, 2, 3, 4, 5]
        b = [[1, 2, 3], [4, 5, 6]]
        c = [0] * (10)
        print(len(a))
        print(len(b))
        print(len(c))
    

if __name__=="__main__":
    MyArray.main([])

Java String to python string method

Java Code

class MyString
{
  public static void main(String[] args)
  {
        String a = new String("Abc");
        String b = "ABC" + "dec";
        // Abc
        System.out.println(a);
        // ABCdec
        System.out.println(b);
      // ABC
        System.out.println(a.toUpperCase());
        // abcdec
        System.out.println(b.toLowerCase());
      
  }
}

Converted Python

class MyString :
    @staticmethod
    def main( args) :
        a =  "Abc"
        b = "ABCdec"
        # Abc
        print(a)
        # ABCdec
        print(b)
        # ABC
        print(a.upper())
        # abcdec
        print(b.lower())
    

if __name__=="__main__":
    MyString.main([])

Java Hashmap to python dictionary

Java Code

import java.util.HashMap;
class MyHashMap
{
  public static void main(String[] args)
  {
    HashMap < String, Integer > hm = new HashMap < String, Integer > ();
    hm.put("One", 1);
    hm.put("Ten", 10);
    hm.put("Year", 2022);
    // {Year=2022, One=1, Ten=10}
    System.out.println(hm);
    // 3
    System.out.println(hm.size());
  }
}

Converted Python

class MyHashMap :
    @staticmethod
    def main( args) :
        hm =  dict()
        hm["One"] = 1
        hm["Ten"] = 10
        hm["Year"] = 2022
        # {Year=2022, One=1, Ten=10}
        print(hm)
        # 3
        print(len(hm))
    

if __name__=="__main__":
    MyHashMap.main([])

How to convert Python to java ?

We were on our way to convert Python to Java. In which we faced some difficulty. That's because, in Python, everyone acts like an object. But Java has its limitations. We can say that the task of converting from Python to Java is not easy, for this you have to keep the following things in mind.

• AST Implementation : There are many ways to implement AST (abstract syntax tree), You can use python ast package to implement AST.

  import ast
  code = "print('I am good')"
  result = ast.parse(code)
  print(ast.dump(result))  
  

  Module(body=[Expr(value=Call(func=Name(id='print', ctx=Load()), args=[Str(s='I am good')], keywords=[]))])

  It does not check unnecessary variable methods and packages. Means it doesn't do error detection which is possible in your code.

  You can also use ANTLR v4 to generate the AST. This too will lack the same type detection. When you use antlr you will feel that it works slowly. But it has many benefits that it also provides your visitors, grammar and visualization.

• Parse Tree Visitor : This is the critical step in which you can control how you represent your code.

• Type Detection

• Package detection

• Syntax Transformation

• Class Decoration

• Loop transformation