Summary - Error handling

Combine try/except/finally and a custom exception to write a bank account class.

Summary - Error handling

In this group you learned five core tools:

try/except — catches errors
else/finally — success and cleanup blocks
raise — throws errors
Exception hierarchy — BaseException → Exception → subclasses
Custom exception — a class derived from Exception

Now you will do two short tasks that combine them: one with raise and multiple except, one with a custom exception.

Exercise raise and multiple except

Inside a try: block write raise TypeError("tür hatası"). Inside an except ValueError: block write print("değer"). Inside an except TypeError: block write print("tür").

Show example solution

try:
    raise TypeError("tür hatası")
except ValueError:
    print("değer")
except TypeError:
    print("tür")

Exercise Define and catch a custom exception

Define class UygulamaError(Exception): with pass in the body. Inside a try: block write raise UygulamaError("hata oluştu"). Inside an except UygulamaError as e: block write print(e).

Show example solution

class UygulamaError(Exception):
    pass

try:
    raise UygulamaError("hata oluştu")
except UygulamaError as e:
    print(e)

Test yourself

Which statement is wrong?
- except catches errors
- else runs when no error
- finally runs only on error
- raise throws errors
Show answer

finally runs only on error — finally always runs — error or no error.
Match error handling

try

Protected code
except

Catches the error
raise

Throws an error
finally

Always runs

Next lesson: import

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