如何将数据框附加到现有的Excel工作表？

Question

该函数被调用多次。 我保留了一个计数，以便在第一次调用它时创建一个工作簿。 然后，我使用pd.ExcelWrite()写入该工作簿。 下次else:执行并打开同一工作簿。 选择其第一张纸，找到其最后一行。 然后将DataFrame写入该行。 这是我的代码：

def WriteFile (df):
  if count1 == 1:
      workbook = xlsxwriter.Workbook('pandas_simple.xlsx')
      writer = pd.ExcelWriter('pandas_simple.xlsx', engine='xlsxwriter')
      df.to_excel(writer, index=False )
      workbook.close()
  else:
      book = open_workbook('pandas_simple.xlsx')
      sheet_names = book.sheet_names()
      sheet = book.sheet_by_name(sheet_names[0])
      row = sheet.nrows
      writer = pd.ExcelWriter('pandas_simple.xlsx', engine='xlsxwriter')
      df.to_excel(writer, index=False, header=False, startrow = row )

我得到这个例外：

Exception Exception: Exception('Exception caught in workbook destructor. Explicit close() 
may be required for workbook.',) in <bound method Workbook.__del__ of <xlsxwriter.workbook.Workbook 
object at 0x000000000A143860>> ignored Exception

执行代码后，我的pandas_simple.xlsx也为空。 我究竟做错了什么？

Answer 1

感谢@ski。

请在同一问题上提及他的答案

如何在不覆盖数据的情况下（使用熊猫）写入现有的excel文件？

import pandas
from openpyxl import load_workbook

book = load_workbook('Masterfile.xlsx')
writer = pandas.ExcelWriter('Masterfile.xlsx', engine='openpyxl') 
writer.book = book
writer.sheets = dict((ws.title, ws) for ws in book.worksheets)

data_filtered.to_excel(writer, "Main", cols=['Diff1', 'Diff2'])

writer.save()

Answer 2

您可以这样操作：

df = pd.DataFrame(np.arange(1, 31), columns=['val'])
fn = 'd:/temp/test.xlsx'
count = 0

writer = pd.ExcelWriter(fn)

for chunk in np.split(df, 3):
    chunk.to_excel(writer, index=False, header=(count==0), startrow=count+(count!=0))
    count += len(chunk)

writer.save()

结果：