How to clear data from Excel worksheets

I am using a loop to clear contents of a worksheet. I am not sure if this is efficient way to do. Can any please guide me with more efficient way to do it.

import openpyxl
wbkName = r’\AA\ AA \ AA \ AA \Python Chart Data.xlsx’# Please change path
wbk = openpyxl.load_workbook(wbkName)

#This loop is used to clear contents of worksheets, I am trying more efficient way for this.
for wks in wbk.worksheets:
for row in wks[‘A1:J10’]:
for cell in row:
cell.value = None #

for wks in wbk.worksheets:# This will write for all the worksheets in workbook
for myRow in range(1, 6):# 6 will give results till row 5 not 6
for myCol in range(1,11):# 11 will give data till column 10
wks.cell(row=myRow, column=myCol).value = myRow
wbk.close ()