Python OpenPyxl Remove a Scatter Chart gridlines? - python-3.x

Question

Python3 and OpenPyxl version 2.3.2
How do you remove a Scatter Chart Gridlines?
from openpyxl.chart.axis import ChartLines
SCchart = ScatterChart()
SCchart.title = "Scatter Chart"
SCchart.style = 13
SCchart.x_axis.majorGridlines = False
gives me the error:
TypeError: expected class 'openpyxl.chart.axis.ChartLines'
And this:
SCchart.x_axis.ChartLines.majorUnit = False
gives the error: AttributeError: 'NumericAxis' object has no attribute 'ChartLines'
I'd like to remove all the chart gridlines.

Answer 1

I have not been able to do this with Openpyxl 2.51, even using some tricks like setting the gridlines to the background color of white (hex 'FFFFFF'). I can get close to accessing the line parameter with openpyxl, but can't quite get it to work. I am including my efforts here, hoping some one else will pick up the ball.
The python gist:
from openpyxl.chart.shapes import GraphicalProperties
# turn majorGridlines off using shapes.GraphicalProperties
sgp = GraphicalProperties(solidFill='FFFFFF') # White
chart.y_axis.majorGridlines.spPr = sgp
This is the XML that openpyxl writes:
<valAx>
<axId val="2" />
<scaling>
<orientation val="minMax" />
<min val="0" />
</scaling>
<axPos val="l" />
<majorGridlines>
<spPr>
<a:solidFill>
<a:srgbClr val="FFFFFF" />
</a:solidFill>
<a:ln>
<a:prstDash val="solid" />
</a:ln>
</spPr>
</majorGridlines>
When I open the spreadsheet that openpyxl just wrote with Excel 2010, the major gridlines are still there with a dark grey color. I click on them and set their color to white and save the file with a new filename. This is how excel writes the new xml code:
<c:valAx>
<c:axId val="83446016"/>
<c:scaling>
<c:orientation val="minMax"/>
<c:min val="0"/>
</c:scaling>
<c:delete val="0"/>
<c:axPos val="r"/>
<c:majorGridlines>
<c:spPr>
<a:ln>
<a:solidFill>
<a:schemeClr val="bg1"/>
</a:solidFill>
<a:prstDash val="solid"/>
</a:ln>
</c:spPr>
</c:majorGridlines>
So logically, you might think that this python would work (spoiler, not for me!):
chart.y_axis.majorGridlines.spPr.ln = sgp
The proper method (the one used by Microsoft) is to set the gridlines to NoFill. Turning off gridlines in excel, saving the file and looking at the chart.xml file yields this:
<c:valAx>
<c:axId val="83031552"/>
<c:scaling>
<c:orientation val="minMax"/>
<c:min val="0"/>
</c:scaling>
<c:delete val="0"/>
<c:axPos val="r"/>
<c:majorGridlines>
<c:spPr>
<a:ln>
<a:noFill/>
<a:prstDash val="solid"/>
</a:ln>
</c:spPr>
</c:majorGridlines>
The python would be something like:
sgp = GraphicalProperties(noFill=True) # bonks, tried None also not effective
chart.y_axis.majorGridlines.spPr.ln = sgp
or maybe
chart.y_axis.majorGridlines.spPr.ln.noFill = True
which also bonks because there is no ln or line in this openpyxl path.

Answer 2

I just found an actual answer that works! You dont need to import ChartLines. The trick was I needed to include another class to get the line thing to work like this:
from openpyxl.drawing.line import LineProperties
# turn majorGridlines off using shapes.GraphicalProperties and drawing.LineProperties
sgp = GraphicalProperties(ln=LineProperties(noFill=True))
chart.x_axis.majorGridlines.spPr = sgp
Try it out!

Answer 3

Not sure if the earlier answers ended this thread, but based on those recommendations and a few tweaks I was able to enable/disable grid Lines for a Line Chart, add data labels.
The following code was used:
from openpyxl.chart.shapes import GraphicalProperties
from openpyxl.drawing.line import LineProperties
from openpyxl.chart.axis import ChartLines
from openpyxl.chart.label import DataLabelList
c1.y_axis.majorGridlines.spPr = GraphicalProperties(noFill = 'True')
c1.y_axis.majorGridlines.spPr.ln = LineProperties(solidFill = '000000')
c1.x_axis.majorGridlines = ChartLines()
c1.x_axis.majorGridlines.spPr = GraphicalProperties(noFill = 'True')
c1.x_axis.majorGridlines.spPr.ln = LineProperties(solidFill = '000000')
c1.dLbls = DataLabelList()
c1.dLbls.showVal = 1
Basically, certain parameters 1st need a class instance to be assigned to them in order to change subsequent sub-parameters.
For ex. When you try to set a value to spPr, the error thrown back will specify the class it expected, which you can then import and assign it's instance to the variable, if I may call it that. Beyond that, the xml can greatly help you figure which variables need to be changed. Hope this helps..

Answer 4

I successfully removed the gridlines from my chart by setting majorGridlines to None.
I included the following two lines in my script.
c1.x_axis.majorGridlines = None
c1.y_axis.majorGridlines = None
In my case, c1 is the instance of openpyxl.chart.LineChart().
I came up with this solution after noticing that majorGridlines accepts None as a value. I noticed this while reading the class definition for _BaseAxis which can be found here:
https://openpyxl.readthedocs.io/en/latest/_modules/openpyxl/chart/axis.html
Below is a full example program. Note: file paths are for windows so you may have to tweak these if you want to run the script on your machine.
# Generate Plots With No Grid Lines
import openpyxl as xl
import numpy as np
from pathlib import Path
# Create Sheet 1 Data
years = np.arange(2000,2023,1)
x1 = np.linspace(0,20,years.size)
x2 = np.linspace(10,2,years.size)
# Create Sheet 2 Data
x3 = np.linspace(10,100,years.size)
x4 = np.linspace(120,50,years.size)
# Open Workbook and Write Sheet 1
wb = xl.Workbook()
sheet = wb[wb.sheetnames[0]]
sheet_one_title = 'Data One'
sheet.title = sheet_one_title
sheet.append(['Year','X1','X2'])
for i in range(0,years.size):
sheet.append([years[i],x1[i],x2[i]])
# Create Sheet 2 and Switch to It
sheet_two_title = "Data Two"
wb.create_sheet(title=sheet_two_title)
sheet = wb[sheet_two_title]
# Write To Sheet 2
sheet.append(['Year','X3','X4'])
for i in range(0,years.size):
sheet.append([years[i],x3[i],x4[i]])
# Now Add The Charts
# Starting With Sheet Two (i.e. "Data Two")
c2 = xl.chart.LineChart()
data = xl.chart.Reference(sheet, min_col=2, min_row=1, max_col=3, max_row=years.size+1)
c2.add_data(data, titles_from_data=True)
dates = xl.chart.Reference(sheet, min_col=1, min_row=2, max_row=years.size+1)
c2.set_categories(dates)
# REMOVE THE GRIDLINES
c2.x_axis.majorGridlines = None
c2.y_axis.majorGridlines = None
# Add Chart to Sheet
sheet.add_chart(c2, 'D5')
# Swtich Back To Sheet 1 (i.e. "Data One")
sheet = wb[sheet_one_title]
# Create Chart
c1 = xl.chart.LineChart()
data = xl.chart.Reference(sheet, min_col=2, min_row=1, max_col=3, max_row=years.size+1)
c1.add_data(data, titles_from_data=True)
dates = xl.chart.Reference(sheet, min_col=1, min_row=2, max_row=years.size+1)
c1.set_categories(dates)
# REMOVE THE GRIDLINES ONCE MORE
c1.x_axis.majorGridlines = None
c1.y_axis.majorGridlines = None
# Add Chart to Sheet
sheet.add_chart(c1, 'D5')
# Get Route to Desktop
desktop = str(Path.home()) + "\Desktop"
# Create Path by Appending File Name
save_path = desktop + "\\PlotExample.xlsx"
# Save Workbook
wb.save(save_path)
print("Workbook Saved To:" + save_path)
p.s. this is my first ever stack overflow answer :)