Exercise 29: What If

Here is the next script of Python you will enter, which introduces you to the if-statement. Type this in, make it run exactly right, and then we'll try see if your practice has paid off.

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people = 20
cats = 30
dogs = 15


if people < cats:
    print "Too many cats! The world is doomed!"

if people > cats:
    print "Not many cats! The world is saved!"

if people < dogs:
    print "The world is drooled on!"

if people > dogs:
    print "The world is dry!"


dogs += 5

if people >= dogs:
    print "People are greater than equal to dogs."

if people <= dogs:
    print "People are less than equal to dogs."


if people == dogs:
    print "People are dogs."

What You Should See

$ python ex29.py 
Too many cats! The world is doomed!
The world is dry!
People are greater than equal to dogs.
People are less than equal to dogs.
People are dogs.
$

Extra Credit

In this extra credit, try to guess what you think the if-statement is and what it does. Try to answer these questions in your own words before moving onto the next exercise:

  1. What do you think the if does to the code under it?
  2. Why does the code under the if need to be indented 4 spaces?
  3. What happens if it isn't indented?
  4. Can you put other boolean expressions from Ex. 26 in the if-statement? Try it.
  5. What happens if you change the initial variables for people, cats, and dogs?

Table Of Contents

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Exercise 28: Boolean Practice

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Exercise 30: Else And If

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