What is the output of python code

Python course


'__pycache __ / my_first_simple_program.cpython-37.pyc' or use the following command at the shell prompt python -m py_compile my_first_simple_program.py In both cases you may notice two things: First, there is a new subdirectory "pycache" in case it doesn't exist yet. In this subdirectory you will find a file "my_first_simple_script.cpython-34.pyc". This is the compiled version of our file in bytecode. You can also compile all Python files automatically with the Compileall module. You can do this from the shell prompt by running compileall.py and specifying the path of the directory that contains the Python files to be compiled: monty @ python: ~ / python $ python -m compileall. Listing. ...

But like I said, you don't have to and shouldn't worry about compiling Python code. The compilation is hidden from the user for good reason. Some newbies sometimes wonder where those ominous files with the .pyc suffix could have come from. If Python has write access to the directory in which the Python program is located, it saves the compiled bytecode in a file that ends with the suffix .pyc. If Python doesn't have write access, the program will still work. The bytecode is generated, but discarded when the program is terminated. Every time a Python program is called, Python checks whether a compiled version with the suffix .pyc is available. This file must be newer than the file with the .py suffix. If there is such a file, Python loads the bytecode, which speeds up the script's start time. If a bytecode version does not exist, Python creates the bytecode before starting the program. Running a Python program means running the bytecode on the Python.

Virtual machine (PVM).

Compilation of a Python script

A bytecode is created every time a Python script is run. When a Python script is imported as a module, the bytecode is saved in the corresponding .pyc file. So in the following no bytecode file is created:

`When importing into the following Python2 session, a bytecode file named" My_first_simple_Python_Program.pyc "is created:

Executable scripts on Linux

Windows users can skip this chapter. Do not worry! It is not essential!

So far we have started our Python scripts with `

on the bash command line. A Python script can also be started like any other script on Linux, e.g. Bash scripts. To do this, two steps are required: The shebang line #! / usr / bin / env python3 needs to be added as the first line of your Python code file. Alternatively, this line can be #! / Usr / bin / python3 if that's the location of your Python interpreter. Instead of using env as in the first line of shebang, the interpreter is searched for and found at the time the script is executed. This makes the script more portable. However, it also has the same problem: the path to env can also be different per machine. The file must be made executable: the "chmod + x scriptname" command must be run on a Linux shell, e.g. Bash. "chmod 755 scriptname" can also be used to make your file executable. In our example:


We illustrate this in a bash session:

Compiler and interpreter

A compiler (also called a translator) is a computer program that translates a program written in a source language such as C or C ++ - called a source or source program - into a semantically equivalent program (target program) of a target language. Usually this is the translation of a source text written by a programmer in a programming language into assembly language, bytecode or machine language. The translation of a source program into a target program by a compiler is also known as compilation.

An interpreter is a program that, unlike assemblers or compilers, does not convert source code directly into executable code, i.e. an executable file, but reads, analyzes and executes the source code. The source code is analyzed while the program is running.


You can also request interactive help for every command and function in the Python interpreter.