Professional IronPython

LISTINg 3-3: 
 Making an either/or decision
# Define an input variable.
Answer = raw_input(‘Say hello (Y/N)?’)
# Check the value of Answer.
if Answer.upper() == ‘Y’:
# Perform some tasks based on a positive response.
print ‘You typed:’, Answer
print ‘So Hello!’
continues
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CHAPTER 3
ImplementIng Structured language elementS
# The user must have typed something else.
else:
# Perform some tasks based on a different response.
print ‘Sorry, you typed:’, Answer, ‘and not Y.’
# Pause after the debug session.
raw_input(‘Press any key to continue...’)
The big thing to notice in this example is that you outdent the 
else
clause and follow it with a 
colon. Every indented statement after the 
else
clause is part of the 
else
portion of the structure. 
The output from this example is similar to the output shown in Figure 3-2. The application asks 
a question and then outputs something based on the response the user provides.
Creating a Decision Tree Using if . . . elif . . . else
Many programming languages provide a special structure to handle complex decisions. IronPython 
keeps things simple by relying on a special form of the 
if
statement, the 
if...elif...else
state-
ment. As you might expect, each 
elif
clause includes a Boolean expression. In many respects, the 
elif
clauses act as the case clauses for the 
Select...Case
structure. Of course, you gain some flexibility 
because the 
elif
clause need not match a particular variable. The 
else
clause acts like the default 
clause for the 
Select...Case
structure. Listing 3-4 shows how to work with the 
elif
clause.