Script for pcbnew to connect unconnected vias to closest pads (currently according to a filter on line 50 - just serves as example)

connect_via_pad.py

import pcbnew
from dataclasses import dataclass

@dataclass
class local_pad_representation:
	pad: object = None
	footprint: object = None
	pos: object = None
	friendly_name: str = None


@dataclass
class local_via_representation:
	via: object = None
	net: object = None
	net_code: int = None
	pos: object = None

def get_pad_list(board):
	pad_list = list()
	for pad in board.GetPads():
		footprint = pad.GetParent()
		pad_list.append(local_pad_representation(
			pad,
			footprint,
			pad.GetPosition(),
			f'{footprint.GetReference()}-{pad.GetName()}',
		))
	return pad_list

def get_via_list(board):
	via_list = list()
	for track in board.Tracks():
		if isinstance(track, pcbnew.VIA):
			via_list.append(
				local_via_representation(
					track,
					track.GetNet(),
					track.GetNet().GetNetCode(),
					track.GetPosition(),
				)
			)

	return via_list

def get_sq_distance(delta):
	return delta.x ** 2 + delta.y ** 2

def test1(board):
	pad_list = [pr for pr in get_pad_list(board) if pr.footprint.GetReference().startswith('RN') or pr.footprint.GetReference().startswith('TVS')]
	via_list = [v for v in get_via_list(board) if v.net_code == 0]

	for via in via_list:
		closest_length = 0
		closest_pad = None
		for p_index, pad in enumerate(pad_list):
			distance = get_sq_distance(via.pos - pad.pos)

			if closest_pad is None or distance < closest_length:
				closest_length = distance
				closest_pad = pad
				
		print(f'Closest {via.pos} - {closest_pad.friendly_name}: {closest_length}')
		via.via.SetNetCode(closest_pad.pad.GetNetCode())