<s>[INST] How to use "raise" keyword in Python So I have read the official definition of "raise", but I still don't quite understand what it is doing. 
In simplest terms, what is "raise"?
A small example of it's use would help too.
 [/INST] It has 2 purposes.
yentup has given the first one.

It's used for raising your own errors.
if something:
    raise Exception('My error!')


The second is to reraise the current exception in an exception handler, so that it can be handled further up the call stack.
try:
  generate_exception()
except SomeException, e:
  if not can_handle(e):
    raise
  handle_exception(e)

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