If I try to open sample file (attached) in read_only mode and try to loop through .rows iterator, it only gives the first row and ignore the rest of the file.
f = open('/home/tejinder/Projects/sales-ingestion/tests/test_files/excel/sales.xlsx', 'rb')
wb = openpyxl.load_workbook(f, read_only=True)
sheet = wb.get_sheet_by_name('Sales Report')
for i in sheet.rows:
(<openpyxl.cell.read_only.ReadOnlyCell object at 0x7f6da17b4110>,)