Can a dictionary key be an integer?

[buran]

import openpyxl
xls_in='in.xlsx'
xls_out='out.xlsx'

wb1 = openpyxl.load_workbook(xls_in) 
active_sheet_wb1 = wb1.active
max_row = active_sheet_wb1.max_row 
 
students_and_scores = {}
for row_num in range(2, max_row +1):
    key = active_sheet_wb1.cell(row=row_num, column=2).value
    students_and_scores[key] = active_sheet_wb1.cell(row=row_num, column=1).value

wb2 = openpyxl.load_workbook(xls_out)
active_sheet_wb2 = wb2.active #get_sheet_by_name(sheetNameswb2[0])
max_row2 = active_sheet_wb2.max_row

for row_num in range(2, max_row + 1): 
    key = active_sheet_wb2.cell(row=row_num, column=1).value
    value = students_and_scores.get(key,'')
    active_sheet_wb2.cell(row=row_num, column=4, value=value)
 
wb2.save('try.xlsx')

this is minimal working script, tested by me. feel free to modify it.