Find all Hidden Subdomains of domains sing python

Sub domain is Part if your domain or any other origination what if you are able to find someone subdomains. there are a lot if tool that can help you to find some of them . DnsMapper is a famous tool that also help Penetration's testers to find sub-domains using Python and Bash DNS Resolver Library. Kali has a lot of tools for this .but the problem is with DnsMapper sometime it not work properly .