<< Chapter < Page Chapter >> Page >
This module introduces control flow in general and explains the use of the while loop in Python.

Table of contents

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.

What you have learned

Earlier modules in this collection have included instruction on the following topics:

  • numbers
  • variables
  • identifiers
  • strings
  • scripts
  • lists
  • tuples

This has prepared you to use Python as a very fancy desk calculator.

What you will learn

The next step in learning to program with Python is to learn how to apply repetition, modularity, and decision logic to your scripts. This is oftenreferred to in computer jargon as control flow .

This module introduces control flow in general and explains the use of the while loop in Python as an example of control flow .

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 Figuresand the Listings while you are reading about them.

(Note to blind and visually impaired students: Most of the Figures and all of the Listings inthis module are presented in plain text format and should be accessible using an audio screen reader or a braille display. Note however that the requiredindentation may not be properly represented by an audio screen reader.)

Figures

  • Figure 1 . Output from the script in Listing 1.
  • Figure 2 . Output from the script in Listing 2.
  • Figure 3 . Visualization of the program.

Listings

  • Listing 1 . Typical script from earlier modules.
  • Listing 2 . Use a while loop to manipulate a list.

General background information

A typical script in the earlier modules looked something like the one shown in Listing 1 .

Listing 1 . Typical script from earlier modules.
# Illustrates extracting a # list element and extracting# elements from a nested list ##------------------------------- print("Create and print a list")listA = [100,200,300,400,500] print(listA)print("Original length is:") print(len(listA))print("Replace an element") listA[2]= [2,4,8,16,32,64] print("Print the modified list")print(listA) print("Modified length is:")print(len(listA)) print("Extract and display each")print(" element in the list") print(listA[0]) print(listA[1]) print(listA[2]) print(listA[3]) print(listA[4]) print("Extract and display each")print(" element in nested list") print(listA[2][0])print(listA[2][1]) print(listA[2][2])print(listA[2][3]) print(listA[2][4])print(listA[2][5])

The output produced by the script in Listing 1 is shown in Figure 1 .

Questions & Answers

if three forces F1.f2 .f3 act at a point on a Cartesian plane in the daigram .....so if the question says write down the x and y components ..... I really don't understand
Syamthanda Reply
hey , can you please explain oxidation reaction & redox ?
Boitumelo Reply
hey , can you please explain oxidation reaction and redox ?
Boitumelo
for grade 12 or grade 11?
Sibulele
the value of V1 and V2
Tumelo Reply
advantages of electrons in a circuit
Rethabile Reply
we're do you find electromagnetism past papers
Ntombifuthi
what a normal force
Tholulwazi Reply
it is the force or component of the force that the surface exert on an object incontact with it and which acts perpendicular to the surface
Sihle
what is physics?
Petrus Reply
what is the half reaction of Potassium and chlorine
Anna Reply
how to calculate coefficient of static friction
Lisa Reply
how to calculate static friction
Lisa
How to calculate a current
Tumelo
how to calculate the magnitude of horizontal component of the applied force
Mogano
How to calculate force
Monambi
a structure of a thermocouple used to measure inner temperature
Anna Reply
a fixed gas of a mass is held at standard pressure temperature of 15 degrees Celsius .Calculate the temperature of the gas in Celsius if the pressure is changed to 2×10 to the power 4
Amahle Reply
How is energy being used in bonding?
Raymond Reply
what is acceleration
Syamthanda Reply
a rate of change in velocity of an object whith respect to time
Khuthadzo
how can we find the moment of torque of a circular object
Kidist
Acceleration is a rate of change in velocity.
Justice
t =r×f
Khuthadzo
how to calculate tension by substitution
Precious Reply
hi
Shongi
hi
Leago
use fnet method. how many obects are being calculated ?
Khuthadzo
khuthadzo hii
Hulisani
how to calculate acceleration and tension force
Lungile Reply
you use Fnet equals ma , newtoms second law formula
Masego
please help me with vectors in two dimensions
Mulaudzi Reply
how to calculate normal force
Mulaudzi
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Itse 1359 introduction to scripting languages: python. OpenStax CNX. Jan 22, 2016 Download for free at https://legacy.cnx.org/content/col11713/1.32
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Itse 1359 introduction to scripting languages: python' conversation and receive update notifications?

Ask