Gerar TXT nome com data

from datetime import datetime

        self.txts=[]

        self.file_name = 'fishfromKML{}.txt'.format(datetime.now().strftime("%Y%m%d%H%M%S%z"))

        self.txts.append(self.nomes)

        with open (self.file_name, 'w') as self.f:

            self.f.write(str(self.txts)) 

self.nomes = ['casa']