python - Delete every non utf-8 symbols from string

Question

I have a big amount of files and parser. What I Have to do is strip all non utf-8 symbols and put data in mongodb. Currently I have code like this.

with open(fname, "r") as fp:
    for line in fp:
        line = line.strip()
        line = line.decode('utf-8', 'ignore')
        line = line.encode('utf-8', 'ignore')

somehow I still get an error

bson.errors.InvalidStringData: strings in documents must be valid UTF-8: 
1/b62010montecassianomcirxe2x86x90ta0xe2x86x90008923304320733/290066010401040101506055soccorin

I don't get it. Is there some simple way to do it?

UPD: seems like Python and Mongo don't agree about definition of Utf-8 Valid string.

Answer 1

Try below code line instead of last two lines. Hope it helps:

line=line.decode('utf-8','ignore').encode("utf-8")