One public and one private method for same functionality

I am looking at source code of mesa, and I see this pattern constantly shows up

def place_agent(self, agent, pos):
    """ Position an agent on the grid, and set its pos variable. """
    self._place_agent(pos, agent)
    agent.pos = pos

def _place_agent(self, pos, agent):
    """ Place the agent at the correct location. """
    x, y = pos
    self.grid[x][y] = agent
    if pos in self.empties:
        self.empties.remove(pos)

Why should we have a separate private method? Especially when there is not real "private" method in python and in both methods we write new values. Is it some kind of design pattern?