Professional IronPython

FIgURE 2-12: 
Not indenting at a secondary prompt produces an error.
4.
Repeat Step 2 again. Press Tab. Type 
print SomeText
and press Enter. This time, the entry 
succeeds, as shown in Figure 2-13. Notice that the interpreter has displayed 
...
again so 
that you can continue the block if desired. In fact, the block continues until you end it by 
not indenting an entry.
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CHAPTER 2
Understanding the ironPython Basics
FIgURE 2-13: 
A properly indented entry succeeds.
5.
Press Enter. The interpreter displays the word Hello. The interpreter will keep track of a 
block until you finish entering the last line of code. It then evaluates the block and performs 
all of the tasks it contains.
Now that you have the basic idea about indentation, it’s time to consider capitalization. IronPython 
is case sensitive. So, if you type:
If SomeText == ‘Hello’:
and press Enter, the code will fail. Figure 2-14 shows that the error information you receive isn’t 
straightforward. All that the interpreter tells you is that the token it received is unexpected (a token
is a single word that the interpreter parses to discover what you want to do). The interpreter will 
provide more precise information for some errors. Type:
if SomeText == ‘Hello’:
print sometext
and press Enter. This time you get precise error information, as shown in Figure 2-15. The inter-
preter tells you that the error lies in line 2 of the block and that the error occurred because 
SomeText
isn’t defined.
FIgURE 2-14: 
Some error messages are ambiguous.
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