Exception Handling with try/except

Sometimes programs crash because of unexpected errors, such as dividing by zero or accessing a file that does not exist.

Instead of crashing, you can use exception handling to deal with errors gracefully.

Python provides four key tools:

• try
• except
• else
• finally

Wrap risky code in a try block. If an error happens, Python jumps to the except block.

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try:
    result = 10 / 0
except ZeroDivisionError:
    print("Oops! You can't divide by zero.")

• The division causes an error.
• Python skips the crash and shows a message instead.

You can catch different types of exceptions in separate except blocks.

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try:
    num = int("abc")
except ValueError:
    print("That's not a valid number.")
except TypeError:
    print("Type mismatch.")

• This handles a ValueError caused by int("abc").

• else runs only if no error occurs.
• finally runs no matter what, even if there is an error.

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try:
    value = int("42")
except ValueError:
    print("Conversion failed.")
else:
    print("Conversion succeeded:", value)
finally:
    print("Done checking.")

• else confirms success.
• finally is good for cleanup, such as closing files or connections.