If you do want to add a specific list of stations to limit downloads...you will need to do the following for now.
In the settings.xml file you will find a setting labeled "slist". You will be adding a list of station ID numbers here. As an example, here is my list:
20377,40462,29024,30697,49377,101904,21213,45740,24028,69874,50770
To get your list of channel/station IDs - run the zap2epg.py program once. It is recommended to just download 1 day and leave "xdetails" set to false. This will generate the xmltv.xml file.
If you open the xmltv.xml file, you will see a list of stations similar to this:
<tv source-info-url="
http://tvschedule.zap2it.com/" source-info-name="zap2it.com">
<channel id="20377.zap2epg">
<display-name>10.1 KGTVDT</display-name>
<display-name>KGTVDT</display-name>
<display-name>10.1</display-name>
<icon src="
http://zap2it.tmsimg.com/h3/NowShowing/20377/s28708_h3_aa.png" />
</channel>
<channel id="64727.zap2epg">
<display-name>10.15 KGTVDT15</display-name>
<display-name>KGTVDT15</display-name>
<display-name>10.15</display-name>
<icon src="
http://zap2it.tmsimg.com/h3/NowShowing/64727/s10003_h3_aa.png" />
</channel>
...
The list is not in any particular order, but you just need to find the channels you want and note the number in the channel id line. For example, channel 10.1 from above has the channel id 20377. This is the number that you will add to the "slist" setting.
Add all the channel id numbers you want to have downloaded, separating each with a comma. That whole list should be entered in the "slist" setting line in the settings.xml file.
I'm sorry for this workaround - it wasn't my original intention to run zap2epg as a standalone program...but it certainly can be reworked to run that way.
Let me know if there are questions, and I will see what I can do to rework the program to be stand alone friendly. Or someone can fork my repo and build it out as desired.