Python raise OSError for missing file or invalid path

RaiseOSError.py

if not os.path.exists(self.path):
    raise OSError(
        errno.ENOENT, os.strerror(errno.ENOENT), self.path
    )

 if not os.path.isfile(self.path + self.file):
     raise OSError(
         errno.ENOENT, os.strerror(errno.ENOENT), self.file
    )