PRG-PY_try_except

  Python3 の エラーハンドリング

https://docs.python.org/ja/3/tutorial/errors.html

>>> while True:
...     try:
...         x = int(input("Please enter a number: "))
...         break
...     except ValueError:
...         print("Oops!  That was no valid number.  Try again...")
...