Refresh Excel Chart External Data Link with Python

Question

I am trying to update the external data link for a chart in Excel using python. The chart sits in workbook1.xlsm and the data it references to update itself sits in external_workbook.xlsx. The reason for the separation is the data has to be updated in workbook1.xlsm periodically using python, which erases the chart if it's in workbook1.xlsm.

I've looked at various solutions but none are working for me so far. The two solutions I've tried so far include (1) refreshing the workbook programmatically and (2) running a macro in the workbook to refresh it programmatically.

Code for (1):

import win32com.client as w3c
xlapp = w3c.gencache.EnsureDispatch('Excel.Application')
xlapp.Visible = 0
xlwb = xlapp.Workbooks.Open(r'{}\{}'.format(path, fname), False, True, None)
xlwb.RefreshAll() # Runs with no errors, but doesn't refresh
time.sleep(5)
xlwb.Save()
xlapp.Quit()

Code for (2):

# ***************** #
# Excel macro - I've verified the macro works when I have the worksheet open.
Sub Update_Links()
    ActiveWorkbook.UpdateLink Name:=ActiveWorkbook.LinkSources
End Sub
# ***************** #

import win32com.client as w3c
xlapp = w3c.gencache.EnsureDispatch('Excel.Application')
xlapp.Visible = 0
xlwb = xlapp.Workbooks.Open(r'{}\{}'.format(path, fname), False, True, None)
xlwb.Application.Run("{}!Module1.Update_Links".format(fname)) # Runs with no errors, but doesn't refresh
xlwb.Save()
xlapp.Quit()

The series for my chart in Excel is

# External data link for Excel chart #
=SERIES(,'...path_to_external_file...[external_workbook.xlsx]Sheet1'!$A$2:$A$2000,
'...path_to_external_file...[external_workbook.xlsx]Sheet1'!$F$2:$F$2000,1)

Could anyone provide me with an alternative solution of how to make this work?

EDIT

So I tried something simpler to test this. I created a new sheet called temp in workbook1.xlsm and tried to write a random value to cell A1 using the code below. The temp sheet is still blank after running the code.

import win32com.client as w3c
import random

xlapp = w3c.gencache.EnsureDispatch('Excel.Application')
xlapp.Visible = 0
xlwb = xlapp.Workbooks.Open(r'{}\{}'.format(path, fname), False, True, None)
books = w3c.Dispatch(xlwb) 

sheet_temp = books.Sheets('temp')
sheet_temp.Cells(1,1).Value = random.random()

xlwb.RefreshAll() # Runs with no errors, but doesn't refresh
time.sleep(5)
xlwb.Save()
xlapp.Quit()

I get no errors with the code and am following examples other people have posted online. Could someone point me to where I'm going wrong with this?

Answer 1

The answer is I needed to open the workbook the external_workbook.xlsx prior to updating the workbook1.xlsm, so the data could be refreshed.

The working code is as follows:

import win32com.client as w3c
import random

xlapp = w3c.gencache.EnsureDispatch('Excel.Application')
xlapp.Visible = 0

# ********************************* #
# New line that fixes it #
xlwb_data = xlapp.Workbooks.Open(r'{}\{}'.format(path, 'external_workbook.xlsx'), False, True, None)
# ********************************* #

xlwb = xlapp.Workbooks.Open(r'{}\{}'.format(path, 'workbook1.xlsm'), False, True, None)
books = w3c.Dispatch(xlwb) 

sheet_temp = books.Sheets('temp')
sheet_temp.Cells(1,1).Value = random.random()

xlwb.RefreshAll() # Runs with no errors, but doesn't refresh
time.sleep(5)
xlwb.Save()
xlapp.Quit()