関連ワード:  check if string is not empty python    how to check if a string is not empty in python    check if string is not null or empty python    check if string is not none or empty python    python check if string is not empty or whitespace    python3 check if string is not empty    python check if string exists and is not empty    python check if variable is not empty string    python check if value is not empty string    python program to check if string is empty or not