関連ワード:  how to validate in python    how to test in python    how to check in python    how to check in python if a number is even or odd    how to check in python if a string contains a substring    how to check in python if a file exists    how to check in python if a number is integer    how to check in python if a string is a number    how to check in python if a variable exists    how to check in python if a list is empty