With openpyxl
version 2.4.0
and pandas
version 0.19.2
, the process @ski came up with gets a bit simpler:
import pandas
from openpyxl import load_workbook
with pandas.ExcelWriter('Masterfile.xlsx', engine='openpyxl') as writer:
writer.book = load_workbook('Masterfile.xlsx')
data_filtered.to_excel(writer, "Main", cols=['Diff1', 'Diff2'])
#That's it!