As BoaBabe already stated, showing your parents that you’re responsible is likely the key. However, if you’ve only had and cared for a snake for 1 month, they’re probably still thinking that you may or may not be responsible, or that your new found hobby is a just a passing fad. Also, they might be still getting used to the whole snake experience themselves. Give them six months to get used to the snake you already have and evaluate your level of responsibility. Yes, I know it sounds like a life sentence, but it’s really not. After that, you should start planting seeds in their ears again.