書き込みと読み込み（基本）

from openpyxl import Workbook ＃Wokbook（大文字）
from openpyxl.utils import get_column_letter # セルからセル番地を取得

wb = Workbook()

dest_filename = 'empty_book.xlsx'

ws1 = wb.active
ws1.title = 'range_names'
# 10行*5列
for row in range(1, 11):
  ws1.append(range(5))

ws2 = wb.create_sheet(title='Pi')
ws2['F5'] = 3.14

ws3 = wb.create_sheet(title='Data')
# セルにセル番地を入力
for row in range(1, 11):
  for col in range(3, 6):
    _ = ws3.cell(column=col, row=row, value='{0}{1}'.format(get_column_letter(col), row))

wb.save(filename = dest_filename)

from openpyxl import load_workbook
wb = load_workbook(filename = 'empty_book.xlsx')

sheet_ranges = wb['range_names']
print(sheet_ranges['D18'])
>>> 3