Data only not working with openpyxl in python

  openpyxl, python, python-3.x

I’m a beginner in Python and I’m developing a program that take some data of a .xlsx and put it into an other .xlsx.
To do so decided to use openpyxl. Here is the beginning of my code :

path1 = "sourceFile.xlsx"
path2 = "targetFile.xlsx"
sheet1 = openpyxl.load_workbook(path1, data_only=True)
sheet2 = openpyxl.load_workbook(path2)

As you can see I use the "data_only=True" to only take the data of my source file. My problem is that with this solution, "None" is returned for few cells of the source file. When I delete the "data_only=True" parameter, the formula is returned, "=B28" in these case. It’s not what I want by the way that B28 cell of the target file has not the same value as B28 cell of source file.

I already search for solutions but surprisedly found nothing. If you have any idea you’re welcomed !

Source: Python Questions