<< Chapter < Page Chapter >> Page >
This module explains the Python loop modifiers: else, continue, break,and pass.

Table of contents


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

You have learned how to construct while loops, for loops, and if statements in recent modules on control flow in Python. In addition, you recently learned how to create nested loop structures .

What you will learn

In this module, you will learn how to add an else clause to while loops and for loops. In addition, once you start using nested loops, you need to know how to use the loop modifiers: continue and break . Those loop modifiers will be explained in this module.

Finally, this module will make a brief mention of the pass statement, which does nothing. If you need to write code that does nothing, the pass statement is for you.

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.)


  • Figure 1 . Output from the code in Listing 1.
  • Figure 2 . Output from the code in Listing 2.
  • Figure 3 . Output from the code in Listing 3.


  • Listing 1 . Loops with else clauses.
  • Listing 2 . Nested loops with a continue statement.
  • Listing 3 . Nested loops with a break statement.

Discussion and sample code

The else clause

You learned about the else clause on an if statement in an earlier module titled Itse1359-1230-The if Statement .

Loop statements can also have an else clause. The else clause on a for loop is executed when the loop terminates through exhaustion of the elements in the list.The else clause on a while loop is executed when the loop terminates because the condition becomes False . The else clause is not executed when the loop is terminated by a break statement.

I will illustrate the else clause using a program that is similar to the odometer program that you learned about in the earlier module titled Itse1359-1250-Nested Loops . The program is shown in Listing 1 .

Listing 1 . Loops with else clauses.
# Illustrates nested loops with else clauses #---------------------------------------------------------------------------leftDigit = 0 rightDigit = 0#Begin outer while loop while leftDigit<2: leftDigit += 1#Begin for loop for middleDigit in range(1,3):rightDigit = 0 #Begin innermost while loopwhile rightDigit<3: rightDigit += 1print(str(leftDigit) + "-" + str(middleDigit) + "-" + str(rightDigit)) else:print("In else clause on inner while loop") #end inner while loop with else clauseelse: print("In else clause on for loop")#end for loop with else clause else:print("In else clause on outer while loop") #end outer while loop with else clauseprint("Goodbye")

Questions & Answers

what are the characteristic of livingthing
Joy Reply
Movement Respiration Nutrition Irritability or sensitivity Growth Excretion Reproduction Adaptation Competition Death or Life Span
what is the function of medulla oblongata
mbalenhle Reply
what is the strongest bone in the human body
what is biology
Dauda Reply
is a branch of science which deals with the study of living thing
Biology is got from two main words: bios: means life and Logos: means knowledge therefore, biology is a branch of science that deals with knowledge, life and functioning of living things.
what are the characteristics of organism
Responds to stimuli
how do we draw a genetic diagram?
Clive Reply
Branches of variation
Mariama Reply
What is variation
Mariama Reply
this is the difference among different species
natural selection was done by who
Faith Reply
by Charles Darwin
Charles Darwin
who proposed Cell doctrine
biology introduction
Khab Reply
describe how the gurd cells regulate the movement of gases in and out of a leaf.
state the main functions of the leaf
kalisto Reply
what is the similarity between meiosis and mitosis
meiosis-involves the division of sex cells mitosis-involves the division of body cells
Regulation of blood sugar level
Kyara Reply
Describes larmack theory
Mayiik Reply
Mention five modes of nutrition in ecology
commercialism mutualism saprophytic parasitic simboitism
what is biology
Imisi Reply
Biology is the study of life
Biology is the study of biography
biology is the branch of science that deal with the study of living organisms
Biology is the branch of science that due with living things and nor living things
Bio means life and logy means to study
what is insulin and where is it found in the body
Cecilia Reply
An illustration of the negative feedback mechanism in homeostasis
How we know
That is not the meaning
what are chromosomes
factor that affect the diffusion of substance
Nwafor Reply
nature of substances size increase in temperature
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?