codigo.py

#!/usr/bin/python3
import base64
import textwrap

fw=open('encoded.txt','w')

with open('/usr/share/wordlists/rockyou.txt', 'r', encoding='utf-8') as f:
    for linea in f:
    	password=str('admin:'+linea)
    	b64 = base64.b64encode(password.encode('utf-8'))
    	s64=str(b64, "utf-8")
    	fw.write(s64)
    	fw.write('\n')

fw.close()