I wrote previously about building dns zone files mostly by querying DNS and saving the results to a file.
The method is not perfect, and it will not be possible to get all the records. In fact, you could get all the records incorporated in the result file if you already have a list and feed it to your code.
I wrote a python module to manage DNS records using the RimuHosting DNS API. The code is hosted at GitHub.
I also added a guessing feature.
The only way to get a full listing of a DNS zone is to use AXFR to request a zone transfer. But that’s usually locked and not available. So building the zone file for a domain is basically guesswork or manual labour at best.
For some background information check out these questions on SO
Here’s a script I wrote to try and automate that as much as possible. Still in beta. Suggestions welcome.
Note: I use DNSPython
Next on my list is using the RimuHosting/Zonomi API to create/import the DNS zone.