To get an ECCN you have to affirmatively apply to the US government for one, so you probably don’t have one It basically certifies that you’ve jumped through some hoops around encryption.
As a general matter, open source software in 2019 typically does not require an ECCN (the big exceptions are software that provide, or heavily use, encryption). I don’t think coverage.py would need one, per discussion here: https://www.bis.doc.gov/index.php/policy-guidance/encryption/2-items-in-cat-5-part-2/a-5a002-a-and-5d002-c-1/iv-5a002-a-1-a-4
If coverage.py did need one (or if someone here is curious), by virtue of being open source you’d still mostly just have to notify the government once, since you’re open source. Good documentation on that here: https://www.magicsplat.com/blog/ear/