sheet value judgment

if (sheet['A'+row_str].value and
                    sheet['B'+row_str].value and
                    sheet['C'+row_str].value and
                    sheet['D'+row_str].value and
                    sheet['E'+row_str].value and
                    sheet['F'+row_str].value and
                    sheet['G'+row_str].value)

if (sheet['A'+row_str].value and
                    sheet['B'+row_str].value and
                    sheet['C'+row_str].value is None and
                    sheet['D'+row_str].value is None and
                    sheet['E'+row_str].value is None and
                    sheet['F'+row_str].value is None):

elif (
                    sheet['A'+row_str].value is None and
                    sheet['B'+row_str].value is None and
                    sheet['C'+row_str].value and
                    sheet['D'+row_str].value and
                    sheet['E'+row_str].value and
                    sheet['F'+row_str].value):