how to put void data to dataframe?

Sorry in advance for my breaking English...

I am now participating in the project that studies on international trade.
I collected all the binary trade data in CSV format. (Reporter countries / Partner countries / trade value)
The problem here is that to conduct regression analysis or other measures, I need "no trade" data along with trade data so that I can figure out the reason for trade. I have collected all the countries ISO (country code) and I want to know if there is a way to make this no trade data into my dataframe.

Thanks a lot for reading my text and I would be really pleased to see your comments...


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