Bolding and coloring rows using xlsxwriter

Here is my current code:

import xlsxwriter

user_input = [["10002",'01/04/23','',"300",'',"300",'','','',"44.44",'','','','',"34232",'','','',"34",'','',"2312"],["10001","01/30/2023","63","15","12345","gatorade","0.1234","a0001","4","50","50","115.4","123","33456","34543","34234","3432","34.22","1800","1800","0","0"]]
#Lists are entered here

column_titles = ['1','2','3','4','5','6','7','8','9','10','11','12','13','14','15','16','17','18','19','20','21','22']

user_input.insert(0, column_titles)
#Adds column titles to be in first row of Excel


workbook = xlsxwriter.Workbook('workbook.xlsx')
worksheet = workbook.add_worksheet()

for row_num, data in enumerate(user_input):
    worksheet.write_row(row_num, 0, data)
#Adds to Excel doc

I have tried to follow <https://xlsxwriter.readthedocs.io/tutorial02.html> and <https://stackoverflow.com/questions/28966420/how-to-set-formatting-for-entire-row-or-column-in-xlsxwriter-python> , but every time I try and edit those to work for my own code, my workbook just comes back blank. Doesn't error out or anything.

This is my first time using xlsxwriter, so I'm not quite sure how to do much yet. I'm trying to take the first row in the spreadsheet, and put it all in bold. (My attempts of this are not in my example code). As well as putting the first 5 columns in the first row, and highlighting those boxes to be blue. Can anybody help me with this?

I'm thinking maybe the way I have the column titles list being appended into the original list may be part of what's complicating this? But I'm unsure. Thank you in advance for any help.

You may need to separate the data writes depending on formatting required.
To add formatting you can create a format and apply that when writing or set to a row or column.<br>
Looking at the header row only given the two requirements;<br>

1. Bold all values
2. First 5 cells highlighted in blue

In the example code below there a two formats the bolding and the cell highlight.<br>
In this case bolding is set to the row (0) i.e. row 1, this line can be added before or after the list is written. The 'set_row' applies the format 'header_row_format' to the whole row from A1 to the last possible column the sheet can contain.<br>
While bolding all the cells in the first row may be OK, higlighting probably wouldn't be notwithstanding your requirement is to only highlight the first 5 anyway. Therefore in this case we can create another format, 'cell_format' and only add this to the first 5 cells as we write the cell values.<br>
If you did only want to bold those cells that you write data to you could include bold as part of the 'cell_format' see commented format line. However in this case you'd need two cell formats one with the bg colour and one without.<br>

import xlsxwriter

column_titles = ['1','2','3','4','5','6','7','8','9','10','11','12','13','14','15','16','17','18','19','20','21','22']

workbook = xlsxwriter.Workbook('workbook.xlsx')
worksheet = workbook.add_worksheet()

header_row_format = workbook.add_format({'bold': True})
worksheet.set_row(0, None, header_row_format)

cell_format = workbook.add_format()
# cell_format.set_bold(True)
cell_format.set_bg_color('blue')

for col_num, data in enumerate(column_titles):
    if col_num < 5:
        worksheet.write(0, col_num, data, cell_format)
    else:
        worksheet.write(0, col_num, data)


workbook.close()