Copy One field content to another Doctype

Hi Experts,

We have created one DocType Called “Location Codes” i.e Items Location in Store.
Hers is the List.

We have Created one new Field in Purchase Receipt Items Doctype Link with Location Codes Doctype.

On receive of material we will feed the location in Purchase Receipt ( Purchase Receipt Item ).
we will need to update this location in item Master.

Have a created a new field in the item master also? You can write a python script which can update the Items Master on submission of the Purchase Receipt.

No i have not created the Field in Item Master, i will create it and where i have to write python code for it .??

You can write the script in file.