Exceptions
try-except
try:
f = open(filename)
...
except IOError, e:
print "Unable to open",filename,e
Different types of exceptions have names (e.g., "IOError")
If an exception of that type occurs in try-block, control passes to the
matching except-block.
Exceptions have values. Placed into optional variable supplied to except.
raise
raise ValueError, "Expected a positive value"
Raises an exception of a given type (e.g., "ValueError").
Accepts an optional value.
This value gets passed back to a matching except statement.
If exception is uncaught, program terminates with an error.
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