What does he mean when he says "blows up" im completly confused with the try: block except: block part of this video.

By "blows Up" he means when the code has an error (an "exception") that isn't handled by the code itself.

To handle exception, that is keep your code from blowing up, you can handle the error within your own code by use the try/except statement. For example, if you want to open a file but the file might not exist, you can wrap the open statement in a try/except then if the file can't be open, your code can take other actions rather than crash.

Some languages prefer you to test for a file's existance before trying the open. Python says 'Go For It!" and just handle the consequences using a try/except block.

Try/excepts can have four parts.

• try -- (required) a block of code to, well, try
• except -- (required) block of code that will immediately execute if something goes wrong in the try block. It is customary to state the exception you are concerned about. For the file missing file case the exception would be FileNotFoundError. Python has many built-in exceptions.
• else -- (optional) block of code that executes if no errors occur in try block
• finally -- (optional) block of code that executes following either the except or the else block

More try/except info here

A 'try/except` statement protects your code anywhere in situations where you don't have control of the situation because your dealing with items outside your code (user input, OS interactions, the return value of other code).