dfをexcelに書き込む

df = pd.DataFrame(np.arange(9).reshape(3,3), columns=['col_' + i for i in list('ABC')])

df
 
>>>   col_A  col_B  col_C
>>>0      0      1      2
>>>1      3      4      5
>>>2      6      7      8

from openpyxl.utils.dataframe import dataframe_to_rows

wb = Workbook()
ws = wb.active

for r in dataframe_to_rows(df, index=True, header=True):
  ws.append(r)
  
wb.save('df_to_openpyxl.xlsx')

# Excel開くと
col_A	col_B	col_C
ここに1行開く			
0	0	1	2
1	3	4	5
2	6	7	8