Develop Reference

What's the difference between executing python code via a task and "Run Python file in Terminal"?

I am just getting my feet wet with Python in VScode. I'd like to know what the difference is between using an extension like the Code Runner Extension (or creating a custom task) to execute Python code and just right-clicking the Python file in the editor pane and selecting, "Run Python file in Terminal or Run current file in Python Interactive Window? What are the pros and cons between the two methods?

its about performance hit
creating a custom task or Run Python file in Terminal
is equal to running python my_code.py in a terminal, and has almost no performance hit
any interactive and second layer for running python has some performance hits, e.g.
Run current file in Python Interactive Window or using an extension like the Code Runner Extension
but don't forget the good things that come along with interactive running and extensions that make these performance hits bearable

The actions you see when right-clicking your file are an implementation of a VSCode extension that you have installed (Python base extension). What ultimately differs depends on the implementation of the specific extension (which you can check only by looking at their implementation) but I think that the main difference is in where your code is getting executed for you, which may be a new interactive window, an integrated terminal or vscode output window.

Run Python file in Terminal simply opens up terminal in vsc in which the python script runs.
The interactive terminal has a ton of fuctions im to afraid of too explain but i have found this neat documentation about that.
https://code.visualstudio.com/docs/python/jupyter-support#_python-interactive-window

When to use the terms python shell and python interpreter?

1) I am new to Python and love to learn its core. I have downloaded the python software package and discovered the python.exe application inside. I double clicked it and a balck and white window popped up.
Should I call it a python Interpreter or python Shell?
2) I am learning python online. I came across the terms python tty, python shell and python interpreter. I am satisfied by calling that screen inside the window as a tty(TeleTYpewriter) because we could use only keyboard to work inside and no mouse. But actually that screen has got some intelligence responding to our request. Is python tty an apt term for it?
3) In UNIX, shell is an user interface and command line interpreter, so does python interpreter and python shell are the same.

Python shell lets you use the Python interpreter in interactive mode, just as an OS shell, such as bash, lets you use the OS in interactive mode. You can use the Python interpreter in script mode or batch mode wherein you let the interpreter execute all lines of code in one sequence. It is comparable to writing shell scripts (or batch files in Microsoft Windows).
In your case the screenshot is of a python "shell".
You shouldn't really pay attention to this distinction because in the end everything runs through the python interpreter be it in interactive mode or not.

It is both the python shell and the python interpreter. The shell is where you write your code directly in the CLI, whereas the interpreter is the program that will interpret your code and execute it. Therefore, the interpreter is called in the shell when you write some code, it may also be called when you execute some python code directly from a file.

The customary term for the interactive Python shell is the Python REPL. Many modern interpreters enter a Read-Eval-Print-Loop when you run them interactively, and this term has stuck.
The program which interprets and executes your Python code is the Python interpreter; it can act as a shell, as described above, or run silently and just execute your Python code without any visible user interface of its own, like when you run a script of yours with
python scriptname.py

iPython automatically at launch in Visual Studio Code on Os X

I would like that iPython run automatically when I launch VSC instead of typing ipython and press enter in the terminal. The answer here How to set ipython/jupyter as the default python terminal for vscode? doesn't work as it is for windows but it shouldn't be really different. Also, is there something similar to the 'Execute' button in Spyder instead of typing %run filename ? Thanks !

I presume you mean you want to run the "Python Interactive Window" and not just an iPython console on startup
There is currently no way to run it on startup. At least no way without writing another extension that would run a command when opening a workspace. It would be simple for us to add one though. Probably a workspace setting. Can you log an issue here:
https://github.com/Microsoft/vscode-python/issues/new
For you second question, 'Execute' in spyder, we have 'Run Current File in Python Interactive Window'. This works on any python file. You can get to it through the context menu on a file or through the command palette.

Sadly the nice workflow of spyder is not provided by any official extension at the moment (as far as I know).
But you can implement the basics easily on your own by writing an extension. Even with no experience in TypeScript you can quickly build an extension which starts an IPython console as soon as you open a python file. I also managed to execute a startup script which implements the runfile method. VS Code also allows keybindings for your functions, so that you can almost work like you can with spyder.
Spyder modified the IPython terminal quite a bit though, so it won't feel exactly the same. But after all, everything there is open source so you could implement it yourself, which is what I'm trying to do in my free time.

how can I configure PyCharm so that running a Python script file is visible for Python Console

I am writing Python scripts in Pycharm with IPython installed. So I can use Python Console in Pycharm to type Python commands and check the immediate output of the codes. However, when I run a script file after pressing 'Run' button (Shift+F10), all the variables and functions are not visible to the Python Console. This is, however, the feature of Spyder, another popular Python IDE. So here is my question: how can I configure Pycharm so that running a Python script file is visible for Python Console? Thanks

You could also run the part of your code you want to test/check in the console by selecting it and then right clicking and clicking on "Execute Selection in Console Alt-Shift-E". That's what I use sometimes when the debugger is not helpful. After running the code (you can also just "run" functions or classes) the console knows the functions and you can use the same features that Spyder has. However, be aware that when you change the code you need to run it in the console once to update the console definitions!

You can not. But you can use pdb (which will break code execution where you need it and you will be able to do the same things, as in the Python Console).
And, which is better and more powerful, you can use PyCharm's debugger. It represents all available variables in tree-like structures and is really handy.

Difference Between Python's IDLE and its command line

What are the key differences between Python's IDLE and its command line environment? IDLE looks nicer, of course, and has some kind of GUI...
Moreover, is IDLE treated the same as the shell? I mean, the shell is the middle layer between the user and Python's interpreter?

They are both the same thing but, IDLE is made to write python code so its better if you can to write on IDLE. You can also try Notepad++ its a pretty good program to write code on.

I am not sure what you question is, but here is a Windows-7 oriented answer of similarity and difference. In the start menu for Python x.y, you can select 'Python x.y (x bits)' to run python interactive in a text-line-oriented console window provided by Microsoft. The console handles key presses and mouse movements and clicks. When you hit , the console sends the line of text to python, which is waiting for input on sys.stdin. When Python processes the line, it sends output to sys.stdout or sys.stderr. This includes '>>> ' and '... ' prompts. The console displays the text for you to see.
In the start menu, you can instead select 'Idle ...'. Unless you have previously selected a different startup option, python run Idle code which uses the tkinter module which used tcl/tk to run a graphical user interface that somewhat imitates the console. The tkinter/tk gui handles key and mouse input and displays output. In both cases, some software besides the Python interpreter itself handles interaction between you and Python.
Some important differences:
Cut, copy, and paste work normally. The Windows console is crippled in this respect.
Idle colors input and output. The Windows console does not.
Idle can display all unicode BMP (the first 64K) chars. The Windows console is limited by code pages.
For 1, 2, and 3, the console of other OSes may do as well or better than Idle.
Idle lets you enter, edit, send, and retrieve complete statements. Interactive python with Windows console only works with physical lines.
Update, 2017/11:
Item 1 above: At least on current Win10, cut, copy, and paste work normally.
Item 3 above: At least on Win10, unicode works better in Command Prompt with 3.6+.
New item 5: The IDLE doc section, also available as Help => IDLE Help now has section '3.3. IDLE-console differences'.

IDLE is a very simple Integrated Development Environment. It runs the same python, libraries etc. as commant-line.
Even more basic (with less features) is IPython. Full feature IDE for Python is, for example, Eclipse with PyDev plugin, or LiClipse.

Python IDLE is where you write your program/s and Python Shell is where you run your program/s.