Execution of a Python Program

Let's assume that we write a Python program with the name x.py. Here, x is the program name and the .py is the extension name. Every Python program is typed with an extension name .py. After typing the program, the next step is to compile the program using Python compiler. The compiler converts the Python program into another code called byte code.

Byte code represents a fixed set of instructions that represents all operations like arithmetic operations, comparison operations, memory related operations, etc., which run on any operating system and hardware. It means the byte instructions are system independent or platform independent. The size of each byte code instruction is 1 byte and hence they are called with the name byte code. These byte code instructions are contained in the file x.pyc. Here, the x.pyc file represents a python compiled file.

The next step is to run the program. If we directly give the byte code to the computer, it cannot execute them. Any computer can execute only binary code which comprises 1s and 0s. Since the binary code is understandable to the machine (computer), it is also called machine code. It is therefore necessary to convert the byte code into machine code so that our computer can understand and execute it. For this purpose, we should use PVM (Python Virtual Machine).

PVM uses an interpreter which understands the byte code and converts it into machine code. PVM first understands the processor and operating system in our computer. Then it converts the byte code into machine code understandable to that processor and into that format understandable to that operating system. These machine code instructions are then executed by the processor and results are displayed.

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