import os
PREFIX = r'c:\asd'
filepath = r'c:\qwe'
filepath = os.path.normpath('/' + filepath).lstrip('/')
full_path = os.path.join(PREFIX, filepath)
print full_path
aW1wb3J0IG9zClBSRUZJWCA9IHInYzpcYXNkJwpmaWxlcGF0aCA9IHInYzpccXdlJwpmaWxlcGF0aCA9IG9zLnBhdGgubm9ybXBhdGgoJy8nICsgZmlsZXBhdGgpLmxzdHJpcCgnLycpCmZ1bGxfcGF0aCA9IG9zLnBhdGguam9pbihQUkVGSVgsIGZpbGVwYXRoKQpwcmludCBmdWxsX3BhdGg=