Tweak how we handle return value from API 'set' method for Vendors

also add note about using `set_vendor()` for creating new ones.

and misc. other cleanup

corepos/api.py

@@ -156,6 +156,12 @@ class CoreWebAPI(object):
         Update an existing Vendor record in CORE.
 
         :returns: Boolean indicating success of the operation.
+
+        .. note::
+           Currently this is being used to create a *new* vendor also.  CORE's
+           ``vendors`` table does not use auto-increment for its PK, which
+           means we must provide one even when creating; therefore this method
+           may be used for that.
         """
         columns['vendorID'] = vendorID
         params = {
@@ -165,10 +171,4 @@ class CoreWebAPI(object):
         }
         response = self.post(params)
         result = self.parse_response(response)
-
-        if result == 'OK':
-            return True
-
-        # TODO: need to see what happens here, when it happens
-        raise NotImplementedError("Unexpected result for set_vendor: {}".format(result))
-        # return False
+        return json.loads(result)

corepos/db/util.py

@@ -2,7 +2,7 @@
 ################################################################################
 #
 #  pyCOREPOS -- Python Interface to CORE POS
-#  Copyright © 2018-2019 Lance Edgar
+#  Copyright © 2018-2020 Lance Edgar
 #
 #  This file is part of pyCOREPOS.
 #
@@ -24,11 +24,9 @@
 CORE POS Database Utilities
 """
 
-from __future__ import unicode_literals, absolute_import
-
 import sqlalchemy as sa
 
-from corepos.db import model as corepos
+from corepos.db.office_op import model as corepos
 
 
 def get_last_card_number(session):