Instructions written in C/C++ are translated directly in a hardware specific machine code. On the other hand, Java/Python instructions are first converted in a hardware independent bytecode and then in turn the virtual machine which is specific to the hardware/operating system converts them in corresponding machine instructions.

The official distribution of Python hosted by https://www.python.org/ is called Cpython. The Python interpreter (virtual machine) software is written in C. We can call it as a C implementation of Python.

There are many alternatives to this official implementation. They are explained as below:

• Jython: Jython is a JRE implementation of Python. It is written in Java. It is designed to run on Java platform. Just as a regular Python module/package, a Jython program can import and use any Java class. Jython program also compiles to bytecode. One of the main advantages is that a user interface designed in Python can use GUI elements of AWT, swing or SWT package.
• Jython follows closely the standard Python implementation. Jython was created in 1997 by Jim Hugunin. Jython 2.0 was RELEASED in 1999. Current Jython 2.7.0 released in May 2015, corresponds to CPython 2.7. Development of Jython 3.x is under progress. It can be downloaded from https://www.jython.org/downloads.html
• IRONPYTHON: IronPython is a .NET implementation of Python. It is completely written in C#. Power of .NET framework can be easily harnessed by Python programs. Python’s rapid development tools are also easily embeddable in .NET applications. Similar to JVM, IronPython runs on Microsoft’s Common Language Runtime (CLR)
• IronPython’s current release, version 2.7.9 can be downloaded from https://ironpython.net/download/
• PyPy: PyPy is a fast, compliant alternative implementation of the Python language. It USES Just-in-Time compiler, because of which Python programs often run faster on PyPy. PyPy programs also consume less space than they do in CPython. PyPy is highly compatible with existing Python code.  PyPy comes by default with support for stackless mode, providing micro-threads for massive concurrency.
• Both CPython 2.x and 3.x compatible versions of PyPy are available for download on https://www.pypy.org/download.html