1.9 Itse1359-1050-introduction to scripts

Table of contents

• Preface
  • Viewing tip
    • Figures
    • Listings
• Introduction
  • Important characteristics of scripts
    • Scripts are reusable
    • Scripts are editable
  • You will need a text editor
  • Combining scripts with interactive mode
• Getting started
  • The location of python.exe
    • Setting the path permanently
    • Setting the path temporarily
      • A Windows batch file
      • Setting the path with a batch file
  • Create a script file
    • Run your script file
    • The correct output
  • Alternative approaches
    • Skulpt
    • Online code visualizer
    • How To Think Like a Computer Scientist
  • Visualize your script file with the Online Python Tutor
• What's next?
  • Practice, practice
  • Cut-and-paste programming
• Miscellaneous

Preface

This module is one in a collection of modules on Python designed for teaching ITSE 1359 Introduction to Scripting Languages: Python at Austin Community College in Austin, TX. It provides an introduction to the use of scripts, and ofnecessity will depart from the interactive mode used in previous modules.

Viewing tip

I recommend that you open another copy of this module in a separate browser window and use the following links to easily find and view the Figures and Listings while you are reading about them.

(Note to blind and visually impaired students: all of the Listings in this module are presented in plain text format and should be accessible using anaudio screen reader or a braille display. However, there are a couple of bitmap images that may not be accessible.)

Figures

• Figure 1 . Screen output from running the script named 1359-1050-01.py.
• Figure 2 . Online Python Tutor visualizerscreen output.
• Figure 3 . Visualizing a program from a future module.

Listings

• Listing 1 . Setting the path temporarily with a batch file.
• Listing 2 . Contents of the file named 1359-1050-01.py.

Introduction

This module provides an introduction to the use of scripts, and of necessity will depart from the interactive mode used in previous modules.

It will be necessary for me to get into a small amount of system stuff that really has nothing in particular to do with Python programming. Rather, it willinvolve getting your computer set up for using scripts with Python.

Up to this point in this collection, I have concentrated on the interactive programming capability of Python. This is a very useful capability that allows you to typein a program and to have it executed immediately in an interactive mode. But, interactive can be burdensome. By now you may have realized that you sometimes find yourself typing the same thing over and over. That is where scripts are useful.

Important characteristics of scripts

Scripts are reusable

Basically, a script is a text file containing the statements that comprise a Python program. Once you have created the script, you can execute it over andover without having to retype it each time.

Scripts are editable

Perhaps, more importantly, you can make different versions of the script by modifying the statements from one file to the next using a text editor. Then youcan execute each of the individual versions. In this way, it is easy to create different programs with a minimum amount of typing.