A Compiler is a special program that translates code written in a high-level language, like Python, to machine code that can be executed by a computer. The goal is to translate the entire code at once and check it for errors, which makes it different from an interpreter that translates the code line by line.

How Compiler Works

Here’s a simplified overview of how a compiler works:

  1. Lexical Analysis: The compiler breaks the whole code into individual words or symbols.

  2. Syntax Analysis: The compiler checks the grammatical structure of the code.

  3. Semantic Analysis: The compiler verifies the code’s logic.

  4. Code Optimization: The compiler optimizes the code to improve the performance of the final program.

  5. Code Generation: The compiler turns the optimized code into machine language.

Remember, Python by default, uses an interpreter, not a compiler. However, compilers for Python do exist and they’re used when you need to distribute your software in a binary format or when you want to optimize your code.


Python compilers include PyPy, Nuitka, and Cython. These compilers are not always necessary, but they can give your code a performance boost.

Here’s a Python code:

1x = 5
2y = 10
3print(x + y)

When compiled, Python generates something called ‘bytecode’. This is a low-level set of instructions that can be executed by the Python interpreter. It’s stored with the ‘.pyc’ extension. On compilation, the above python code will convert into bytecode, which is ready to run by the machine.

Did you know?

Python automatically compiles your Python file into bytecode when you import a module, thereby speeding up the start-up time of running your Python script.