Cell Format for a range of cells using xlsxwriter
I need format a range of cells without using worksheet.write function as the data is already present in cells.

In general that isn't possible with XlsxWriter. If you want to specify formatting for cells then you need to do it when you write the data to the cells.
There are some options which may or may not suit your needs:

Row and Column formatting. However that formats the rest of the row or column and not just the cells with data.
Add a table format via add_table().
Add a conditional format via conditional_format().

However, these are just workarounds. If you really need to format the cells then you will need to do it when using write().
I am using xlsxwriter to export pandas dataframe to excel file. I need format a range of cells without using worksheet.write function as the data is already present in cells.
If I am using set_row or set_column, it is adding the format to entire row or column.
Please help me find a solution.