What I have in mind to do is in theory really straightforward, only Zoho APIs have historically proven difficult to navigate for me. 

So we have a custom module that stores a numeric value in 2 different formats.

One format starts with "123XXXXX".

The other format starts with "456XXXXX".

What I'm trying to do is to fetch all the records that start with "123", and replace only these 3 digits at the start with "456". 

That's it. I think it might be possible to also do this in Deluge, although I'm much more comfortable in Python. 

If anyone could point me to the precise API calls I'd need to be making, that would be great. The technicalities of how to go about calling each query in this record, and then updating it only if it meets conditions are what I need help with. The documentation and example codes are often really difficult for me to make sense of!