Python exceptions

A try block runs code that might fail; its except catches the error and lets the program carry on, instead of stopping.

Catch the error you expect, by name: ValueError for int("abc"), ZeroDivisionError for dividing by 0.

for line in ["4", "x", "7"]:
    try:
        print(int(line) * 2)
    except ValueError:
        print("not a number")

Watch for: A bare except: hides every mistake, your own typing errors too. Name the error.