import openpyxl
#Opening a Workbook
wb = openpyxl.load_workbook('file.xlsx')
#Working with an specific sheet.
Sheet = wb.get_sheet_by_name('Data')
#Getting the max amount of rows in a given sheet.
row_count = Sheet.max_row
#GEO_CODE home_county
for i, cellObj in enumerate(Sheet['T'], 1):
cellObj.value = '=A{0}'.format(i)
#Total_Count
for i, cellObj in enumerate(Sheet['U'], 1):
cellObj.value = '=SUMIF($A$2:$A${1}, T{0},$D$2:$D${1})'.format(i, row_count)
wb.save('file.xlsx')