title: Python Plotly, how to remove background horizontal line?
body: <p>How to get rid of the background horizontal lines on this chart? The lines that represent the scales 5, 10, 15, etc. You can find the code below:</p>
  
  <p><a href="https://i.stack.imgur.com/A4nkf.png" rel="noreferrer"><img src="https://i.stack.imgur.com/A4nkf.png" alt="enter image description here"></a></p>
  
  <pre><code># Plotting waterfall chart for Years of Experience lost on DA Team
  
  x_data = ['A', 'B', 'C', 'D', 'E']
  y_data = [13, 23.5, 17.5, 10, 2.5] # y_data for positioning the annotations
  text = ['27', '7', '5', '10', '5']
  
  # Base
  Base = go.Bar(x=x_data, y=[0, 20, 15, 5, 0], marker=dict(color='rgba(1,1,1,     0.0)',))
  # Total
  Total = go.Bar(x=x_data, y=[27, 0, 0, 0, 0],     marker=dict(color='#003A6F',line=dict(color='k',width=1,)))
  # Individuals
  Individuals = go.Bar(x=x_data, y=[0, 7, 5, 10, 0], marker=dict( color='#FFE512',line=dict(color='k',width=1,)))
  # Years of Experience Left
  Years_left = go.Bar(x=x_data, y=[0, 0, 0, 0, 5],  marker=dict(color='00AB39',line=dict(color='k',width=1,)))
  
  # Put all traces in one "data" list
  data = [Base, Total, Individuals, Years_left]
  
  # Layout takes care of things like chart title, x and y axis titles and font     sizes, etc.
  layout = go.Layout(
      title='Chart One',
      barmode='stack',
      yaxis=dict(title='Number of Years', titlefont=dict(size=yaxis_font_size)
                                , tickfont=dict(size=yaxis_font_size)),
      xaxis=dict(title='Names', titlefont=dict(size=xaxis_font_size)
                                , tickfont=dict(size=yaxis_font_size)) ,   
      showlegend=False
  )
  
  annotations = []
  annotations_colors = ['rgba(245, 246, 249, 1)', 'k', 'k', 'k', 'rgba(245,     246, 249, 1)'] # assign colors to annotations
  for i in range(0, 5):
      annotations.append(dict(x=x_data[i], y=y_data[i], text=text[i],     font=dict(family='Arial', size=14, color=annotations_colors[i]),     showarrow=False,))
      layout['annotations'] = annotations
  
  fig = go.Figure(data=data, layout=layout) # Standard plotly way to assign     data and layout
  iplot(fig, filename='Chart One')
  </code></pre>
  
  <p>Thanks!</p>