Question

So I downloaded the Python program but I'm having trouble with IDLE. I need to have both programs correct?

Answer 1

There are two windows where you can write code.

In Python Shell the evaluation and execution of statements is immediate and is not ideal for writing actual code but for executing portions of already written code.

The empty Editor window named 'Untitled' is where you should write code as it is easy to modify and save code there.

Now about which program should be correct -
Whenever you execute a program from Editor window, the shell restarts, so all you have already written in shell doesn't matter, but what you write next matters.
If your program in Editor window had some functions, you can call them here which itself can be considered as writing a program and that too must be done correctly.

Answer 2

Also, the version of Python they offer on the OCW site is outdated (they offer version 2.5.x, but now the customary standard is 2.7.x) and (I think) no longer comes with all required libraries. I suggest you use the canopy distribution which has things like pylab, numpy, and matplotlib already installed.
https://www.enthought.com/products/epd/free/

Answer 3

You need the Python interpreter (if you have Windows). You don't need IDLE, you can use any plain text editor (not a word processor, they embed formatting and font information in the file). Notepad will work fine.

Answer 4

When you downloaded python and installed it, IDLE was also installed as part of the software installation package. It is not an executable .exe file to pin, or shortcut to. It is automatically installed in your start menu ( earlier versions of windows) or in your Main Desktop(,down arrow) under python programs ( Windows 8+)
Starting the IDLE opens up a shell window, to run command line functions/inputs in a gui environment, while clicking file, new will provide you with a text editor to code, and run your test programs if you do not wish to use text editors outside python. read the instructions pdf's at the installations page here on this site for help in beginning python.
http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-00-introduction-to-computer-science-and-programming-fall-2008/assignments/getting_started.pdf