Exception order and broad handlers

The order of except blocks matters, and broad handlers such as except Exception: can hide real bugs. A handler that is too general can catch errors you did not mean to recover from.

What is happening?

try:
    value = int("abc")
except Exception:
    print("Something went wrong")
except ValueError:
    print("Bad number")

This ValueError handler is effectively unreachable because Exception catches it first.

Why this matters

Broad exception handling can make code look stable while quietly swallowing problems such as:

• type mistakes
• programming errors
• unexpected library failures
• bugs that deserve to crash loudly during development

It also makes debugging harder because the original error path is blurred.

Prefer narrow exception handling

Catch the specific error you expect:

try:
    value = int("abc")
except ValueError:
    print("Bad number")

If you need several handlers, put more specific exceptions first and broader ones later.

try:
    ...
except ValueError:
    ...
except Exception:
    ...

Even then, a broad final handler should usually log clearly or re-raise unless there is a strong reason to suppress the error.

Rules of thumb

• Catch the most specific exception you can.
• Order except blocks from specific to general.
• Be cautious with except Exception:.
• Do not hide programming mistakes behind recovery code meant for expected failures.