title: How to add points or markers to line chart using plotly express?
body: <p>plotly.express is very convenient to produce nice interactive plots. The code below generates a line chart colored by country.  Now what I need is to add points to the plot. Does anyone know how I can add points to the line chart?</p>
  
  <pre><code>import plotly.express as px
  
  gapminder = px.data.gapminder().query("continent=='Oceania'")
  fig = px.line(gapminder, x="year", y="lifeExp", color='country')
  fig.show()
  </code></pre>