public class Example {
    private static void permute(int n, char[] a) {
        if (n == 0) {
            System.out.println(String.valueOf(a));
        }
        else {
            for (int i = 0; i <= n; i++) {
                permute(n - 1, a);
                swap(a, n % 2 == 0 ? i : 0, n);
            }
        }
    }

    private static void swap(char[] a, int i, int j) {
        char saved = a[i];
        a[i] = a[j];
        a[j] = saved;
    }

    public static void main() {
        char[] a = "Hello world".toCharArray();
        permute(5, a);
    }
}

public class Example                                   {
    private static void permute(int n, char[] a)       {
        if (n == 0)                                    {
            System.out.println(String.valueOf(a))      ;}
        else                                           {
            for (int i = 0; i <= n; i++)               {
                permute(n - 1, a)                      ;
                swap(a, n % 2 == 0 ? i : 0, n)         ;}}}
    
    private static void swap(char[] a, int i, int j)   {
        char saved = a[i]                              ;
        a[i] = a[j]                                    ;
        a[j] = saved                                   ;}
    
    public static void main()                          {
        char[] a = "Hello world".toCharArray()         ;
        permute(5, a)                                  ;}}

git clone https://github.com/20toduc01/pythonify.git
cd pythonify

python pythonify.py [-h] -i INPUT -o OUTPUT [-s INDENT_SIZE] [-e EOL_SPACE] 

python pythonify.py -i Example.java -o output.java

from pythonify import pythonify

pythonify('example.cpp', 'output.cpp', indent_size=4, eol_spacing=1)