Step: Exception handling: try / except

try:/except ExceptionType: runs code that might fail and recovers instead of crashing the whole program.

Why it matters: real input is messy — try/except lets you skip or handle bad data instead of letting one bad value kill the run.

Example: int("abc") raises ValueError; wrapping it in try/except ValueError lets you handle it gracefully.

Your turn: sum the numeric strings in values, printing a message and skipping any that aren't valid integers.

Pitfall: a bare except: (no type) catches everything, including typos like NameError — always name the specific exception you expect.