Python: Excel Read xls xlsx / Write xlsx

import xlrd, xlsxwriter

# open files
workbook_in = xlrd.open_workbook('C:/Users/UserBob/Downloads/12661.xlsx')
workbook_out = xlsxwriter.Workbook('test.xlsx')

# create formats for output
header_format = workbook_out.add_format()
header_format.set_bold()
header_format.set_bg_color('#808080') # gray
url_format = workbook_out.add_format({
    'font_color': 'blue',
    'underline':  1
})
url_format.set_bg_color('#ffffff')

#copy sheets
sheet1 = 'Detail'
sheet2 = 'Summary'
for sheet_index in range(workbook_in.nsheets):
    #copy sheet
    sheet_in = workbook_in.sheet_by_index(sheet_index)
    sheet_name = sheet_in.name
    sheet_out = workbook_out.add_worksheet(sheet_name)
    sheet_out.set_column('A:G', 30) # set column spacing for sheet_out
    num_rows = sheet_in.nrows
    num_cells = sheet_in.ncols

    print(sheet_name)
    if sheet1 in str(sheet_name):
        # grab header names
        headers = [item.lower() for item in sheet_in.row_values(0,0)]
        jnumber_index = headers.index('item')
        title_index = headers.index('item description')
        # # grab uts numbers create urls
        uts_nums = []
        for jnumber in sheet_in.col_values(jnumber_index,0):
            uts_nums.append(jnumber[1:6])
        for i,uts in enumerate(uts_nums):
            uts_nums[i] = "http://url.com/product/"+str(uts)+".jpg"
        # iterate rows
        for row_index in range(num_rows):
            row = sheet_in.row_values(row_index)
            #iterate cells
            for cell_index, cell_value in enumerate(row):
                # if title index write urls
                if (cell_index is title_index) and (row_index is not 0):
                    #write urls
                    print('Writing URL')
                    sheet_out.write_url(row_index, cell_index,uts_nums[row_index],url_format,str(row[cell_index]))
                elif row_index is 0:
                    sheet_out.write(row_index,cell_index, str(cell_value),header_format)
                else:
                    print('Writing.')
                    sheet_out.write(row_index,cell_index, str(cell_value))
    elif sheet2 in str(sheet_name):
        #iterate rows
        for row_index in range(num_rows):
            row = sheet_in.row_values(row_index)
            # iterate cells
            for cell_index, cell_value in enumerate(row):
                if row_index is 1:
                    sheet_out.write(row_index,cell_index, str(cell_value), header_format)
                elif ('total' in row) or ('Total' in row):
                    sheet_out.write(row_index,cell_index, str(cell_value), header_format)
                else:
                    sheet_out.write(row_index,cell_index, str(cell_value))

# check
import pdb;pdb.set_trace()
# write test with:
# workbook_out.close()