Python try except

Basic try/except

Code that might fail goes inside the try block. If an exception occurs, Python immediately jumps to the matching except block instead of stopping the whole program.

try:
    result = 10 / 0
except ZeroDivisionError:
    print("You cannot divide by zero!")

Catching Specific vs Broad Exceptions

Always try to catch the most specific exception type you expect, like ValueError or KeyError. A bare except: (or except Exception:) catches everything, including bugs you did not anticipate, which can hide real problems.

try:
    age = int(input("Enter your age: "))
except ValueError:
    print("Please enter a valid whole number.")

Handling Multiple Exception Types

You can stack several except blocks to handle different error types differently, or group related types in one tuple.

try:
    data = {"marks": 90}
    value = int(data["name"])
except KeyError:
    print("That key does not exist.")
except (ValueError, TypeError):
    print("The value could not be converted.")

else and finally

The else block runs only if the try block succeeds with no exception. The finally block always runs — whether an exception happened or not — making it perfect for cleanup work like closing a file or a database connection.

try:
    number = int("42")
except ValueError:
    print("Conversion failed")
else:
    print("Conversion succeeded:", number)
finally:
    print("This always runs, error or not.")

• try holds risky code that might raise an exception.
• except catches and handles a specific exception type.
• else runs only when no exception occurred.
• finally always runs, useful for cleanup like closing files.