1.9 Itse1359-1050-introduction to scripts  (Page 2/4)

You will need a text editor

Just about any text editor will suffice for creating Python script files and you may already have a favorite. Whichever editor you choose, make certain that it produces plain ASCII textin its output (no bold, no underline, no italics, etc.) .

In addition to functioning as an interactive interface, the IDLE GUI interface also provides a text editor for creating scripts. Once youhave the GUI interface open, select New File from the File menu. After that, the behavior is similar to many other text editors.

Combining scripts with interactive mode

It is also possible to combine script files with interactive mode to incorporate pre-written scripts into interactive programs.

Getting started

In order to use script files, you must prepare you computer to use them or you must pursue one of the alternative approaches described later. Preparing your computer for use with Pythondoesn't amount to much in the way of effort, but it is critical. All of the following instructions are based on the Windows operating system. If you areusing some other operating system, you will need to translate the instructions for use with that operating system.

The location of python.exe

When you first installed your Python software, a directory should have been created somewhere on your hard drive containing a file named python.exe . You will need to locate that file. On my Windows machine, the file islocated in the following folder:

C:\Program Files (x86)\Python34

Setting the path permanently

In case you are unfamiliar with the term, the "path" is a text string, otherwise known as an environment variable , that tells the operating system where to search for executable files such as the file named python.exe .

You will need to cause the directory containing the file named python.exe to be listed in your system environment variable named path , either permanently or temporarily.

If you already know how to set the path, and you want to make a permanent change to the path, go ahead and do it. If you don'talready know how, you may need to get some help.

I'm not going to try to tell you how to make a permanent change to the path. If you don't do it correctly, you maycause problems that are difficult to recover from. I don't want to be responsible for that. However, I will tell you how to make a temporary change to thepath in the next section.

Setting the path temporarily

A Windows batch file

A Windows batch file is an executable text file with an extension of .bat. In its simplest form, it contains one or more commands that you would otherwiseenter, one at a time, at the command-line prompt. When you execute the batch file, it attempts to cause those commands to be executed sequentially andautomatically.

I am a big believer in the use of batch files for a variety of reasons, not the least of which is the ability to type a set of commands once and to executethem many times without having to retype them.

Batch files also make it possible to execute commands on the command line in the "current directory" without therequirement to go through the steps that are normally required to open a command-line window and navigate to the current directory.