将 Pandas DataFrame 附加到现有 Excel 文档

Question

根据 https://github.com/pandas-dev/pandas/pull/21251/files/09e5b456e1af5cde55f18f903ab90c761643b05a，我们应该能够将数据帧附加到新的 XLSX 工作表。

根据文档，我尝试了以下操作：

>>> import pandas as pd
>>>                
... d1 = pd.DataFrame({"A":['Bob','Joe', 'Mark'], 
...                "B":['5', '10', '20']})
>>> d2 = pd.DataFrame({"A":['Jeffrey','Ann', 'Sue'], 
...                "B":['1', '2', '3']})
>>> 
>>> # Create XLSX document for ticker
... writer = pd.ExcelWriter('test.xlsx',engine='openpyxl')
>>> d1.to_excel(writer,sheet_name='d1')
>>> writer.save()
>>> 
>>> writer = pd.ExcelWriter('test.xlsx',engine='openpyxl', mode='a')
>>> d2.to_excel(writer,sheet_name='d2')
>>> writer.save()
>>> 
>>> pd.__version__
'0.23.4'     # Just updated this per a comment
>>> 
>>>

结果是一个名为 'test.xlsx' 的工作簿，只有一个选项卡 'd2'。

如何防止 workbook/sheet 表单被覆盖？

Answer 1

您可以使用 with:

with pd.ExcelWriter('test.xlsx', engine='openpyxl', mode='a') as writer:
    d1.to_excel(writer,sheet_name='d1')
    d2.to_excel(writer,sheet_name='d2')
    writer.save()

writer.close()

更新

这应该可以工作，但请注意需要事先创建一个空白文件。如果需要，您可以使用 python 创建一个空白文件。我创建了一个简单的循环，以某种方式模仿您要完成的任务的本质：

import pandas as pd
from openpyxl import load_workbook

d1 = pd.DataFrame({"A":['Bob','Joe', 'Mark'], 
               "B":['5', '10', '20']})
d2 = pd.DataFrame({"A":['Jeffrey','Ann', 'Sue'], 
                "B":['1', '2', '3']})

dfs = [d1,d2]

for i in range(len(dfs)):
    sheet = 'd'+str(i+1)
    data = dfs[i]
    writer = pd.ExcelWriter('atest.xlsx',engine='openpyxl', mode='a')
    writer.book = load_workbook('atest.xlsx') # here is the difference
    data.to_excel(writer,sheet_name=sheet)
    writer.save()
    writer.close()

或者这里是修改后的第一个例子：

d1 = pd.DataFrame({"A":['Bob','Joe', 'Mark'], 
               "B":['5', '10', '20']})
d2 = pd.DataFrame({"A":['Jeffrey','Ann', 'Sue'], 
                "B":['1', '2', '3']})

writer = pd.ExcelWriter('atest.xlsx', engine='openpyxl', mode='w')
d1.to_excel(writer,sheet_name='d1')
writer.save()
writer.close()

writer = pd.ExcelWriter('atest.xlsx', engine='openpyxl', mode='a')
writer.book = load_workbook('atest.xlsx')
d2.to_excel(writer,sheet_name='d2')
writer.save()
writer.close()

Answer 2

我在 GitHub 上提交了 post 并收到了贡献者的回复（请参阅下面突出显示的部分）。事实证明，此功能要到 0.24 才会发布，因此在 0.23.1 中不可用。仅供参考 - 我下载了 RC 并成功尝试了 mode='a' 选项。但是，不存在的工作簿可能存在错误；我收到 FileNotFoundError: [Errno 2] No such file or directory: 'test.xlsx'.

"this feature is being released as part of 0.24 which we just issued a release candidate for over the past few days. You can try on the RC or here on master and if neither works open an issue per the contributing guide, but this wouldn't be expected to work on versions older than that"

Answer 3

导入 pandas 作为 pd

writer = pd.ExcelWriter(wk_path + save_file)
# ....
# build sc_files DataFrame and save. sc_files includes
# a column called OS.

sc_file.to_excel(writer, sheet_name='test')

# build data frame of OS counts out of sc_file
counts_os = sc_file.OS.value_counts() 

# To append to 'test' sheet, use startcol=x1, startrow=y
# To append counts_OS to the end of the current 'test' sheet
y = len(sc_file)
y += 1
counts_os.to_excel(writer, sheet_name='test', 
    startcol=1, startrow=y)

# write counts_os to sheet test2 
counts_os.to_excel(writer, sheet_name='test2')
writer.save()
writer.close()

将 Pandas DataFrame 附加到现有 Excel 文档

Appending Pandas DataFrame to existing Excel document

python

excel

pandas

xlsxwriter

更新