title: Openpyxl chart axis in percent
body: <p>I'm creating charts in excel using openpyxl and I want some of my charts to have y-axes with the units in percent. Is this possible in openpyxl? It's quite easy in xlsxwriter, but I can't figure out how to do it in openpyxl. The code below is for a chart with two y-axes.</p>
  
  <p>Thanks!</p>
  
  <p><strong>Edit:</strong></p>
  
  <p>Turns out it was as simple as changing the format of the y_axis, at least for this problem.</p>
  
  <pre><code>c2.y_axis.number_format = '0%'
  
  
  def line_chart_2axis(sheet_name, file_name):
      font = Font(color = "000000", size = 8.5, name = 'Avenir Next Condensed Regular')
      c1 = LineChart()
      data1 = Reference(data_sheet, min_col=3, min_row=1, max_col=3, max_row=len(df1)+1)
      dates = Reference(data_sheet, min_col=1, min_row=2, max_col=1, max_row=len(df1)+1)
      c1.add_data(data1, titles_from_data=True)
      c1.title = "Title"
      c1.style = 5
      c1.y_axis.title = 'Y Axis 1'
      c1.x_axis.number_format = 'Mmm-YYYY'
      c1.set_categories(dates)
      c1.y_axis.majorGridlines = None
      c1.legend.position = 'b'
      s1 = c1.series[0]
      s1.graphicalProperties.line.width = 14000
      s1.graphicalProperties.line.solidFill = "8989ff"
      c2 = LineChart()
      data2 = Reference(data_sheet, min_col=2, min_row=1, max_col=2, max_row=len(df1)+1)
      c2.add_data(data2, titles_from_data=True)
      c2.y_axis.axId = 200
      c2.y_axis.title = "Y Axis 2"
      c2.y_axis.crosses = "max"
      c2.y_axis.majorGridlines = None
      s2 = c2.series[0]
      s2.graphicalProperties.line.width = 14000
      s2.graphicalProperties.line.solidFill = "000062"
      c1 += c2
      sheet.add_chart(c1, "B2")
  </code></pre>