Simple OOP currency converter - follow-up
Set?

You have logic preventing duplicate currency pairs. The easier (and more performant) thing to do is to simply represent pair_currencies as a set instead of a list. When you add, it will automatically discard duplicates.

snake_case

The standard is to name methods like your last_pair - i.e., get_rate.

Lookups

You have a loop in getRate and editRate to try and find the correct currency. Instead, you should be using a dictionary, which does not require a loop.

Remove duplicate methods

editRate and setRate do the exact same thing, so delete the former.

Equality test is wrong

Your __eq__ method should be comparing to an object instance, not a string. As such, you should be comparing self.name with object.name.