Fix for filter filename not found or not string

[N0D3J1TQU0]

No description provided.

[cmancone]

This change doesn't quite make sense to me. What is the value of filename that is causing you trouble? Your proposed change is going to break an important input check.

[N0D3J1TQU0]

mmmm in my case if instances were not working because type('') returned "unicode". I just printed type(filename) across all the script and noticed it was always an string instance. So this modification worked for me

[N0D3J1TQU0]

This was my problem, even with filters format, directory, and call adress were supposedly correct
ValueError: Please pass the filename for the filter transmission file!

[cmancone]

filters should already be a list, so wrapping it in brackets is only going to completely change the meaning of this for loop. What exactly is the problem you are trying to address with this change?

[N0D3J1TQU0]

yeah i think this problem was solved with the type(str('')) change. Since if instances were not working, filters reach this line as a string. Since I was too paranoid I just upload all the modifications (i.e. this is not raising an error to me probably because not using that definition or if instance).
Sorry for ambiguity, rookie github user here.

[cmancone]

This whole type(str('')) thing doesn't make much sense, so it would really be good to understand what is different in your case to cause this issue. I don't like making changes without understanding why, because that's a good way to break things or to hide the root issue. Try running the following locally vs an online python executor (e.g. online-python.com):

print(type('') == type(str('')))

They are exactly equal, which means that your change doesn't actually change anything.

If for some reason there was a weird edge case where the type of '' was not a string, then I'd just as soon change the check to:

type(filename) == str

Which is a bit more clear anyway. However, I still don't want to do that for no reason, and I don't understand why your proposed change would actually change anything.

[N0D3J1TQU0]

Yes, they are exactly the same! its probably a problem related to my conda environment, dependencies, etc...
I can't tell exactly what the problem is or which outdated package is generating the problem, but still type(filename) == str (that is indeed more clearly) solved my problem. If it's okey with you this branch should stay open, idk, maybe it will help someone with the same problem or maybe someone will adress what the real problem is.