Author Dusty Phillips Reviewers

else:
print("This code called if there is no exception")
finally:
print("This cleanup code is always called")
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Chapter 4
[
 107 
]
If we run this example—which illustrates almost every conceivable exception 
handling scenario—a few times, we'll get different output each time, depending
on which exception 
random
chooses. Here are some example runs:
$ python finally_and_else.py
raising None
This code called if there is no exception
This cleanup code is always called
$ python finally_and_else.py
raising
Caught a TypeError
This cleanup code is always called
$ python finally_and_else.py
raising
Caught some other error: IndexError
This cleanup code is always called
$ python finally_and_else.py
raising
Caught a ValueError
This cleanup code is always called
Note how the 
print
statement in the 
finally
clause is executed no matter what 
happens. This is extremely useful when we need to perform certain tasks after 
our code has finished running (even if an exception has occurred). Some common 
examples include:
• 
Cleaning up an open database connection
• 
Closing an open file
• 
Sending a closing handshake over the network
The 
finally
clause is also very important when we execute a 
return
statement 
from inside a 
try
clause. The 
finally
handle will still be executed before the
value is returned.
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Expecting the Unexpected