如何在不覆蓋數據的情況下寫入現有的 excel 文件（使用熊貓）？

Question

我使用 pandas 按以下方式寫入 excel 文件：

import pandas

writer = pandas.ExcelWriter('Masterfile.xlsx') 

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

writer.save()

Masterfile.xlsx 已經包含許多不同的選項卡。 但是，它還不包含“Main”。

Pandas 正確寫入“主”工作表，不幸的是它也刪除了所有其他選項卡。

Answer 1

Pandas 文檔說它對 xlsx 文件使用 openpyxl。 快速瀏覽ExcelWriter的代碼會發現這樣的事情可能會奏效：

import pandas
from openpyxl import load_workbook

book = load_workbook('Masterfile.xlsx')
writer = pandas.ExcelWriter('Masterfile.xlsx', engine='openpyxl') 
writer.book = book

## ExcelWriter for some reason uses writer.sheets to access the sheet.
## If you leave it empty it will not know that sheet Main is already there
## and will create a new sheet.

writer.sheets = dict((ws.title, ws) for ws in book.worksheets)

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

writer.save()

Answer 2

更新：從 Pandas 1.3.0 開始，以下函數將無法正常工作，因為函數DataFrame.to_excel()和pd.ExcelWriter()已更改 - 引入了新的if_sheet_exists參數，該參數使下面的函數無效。

在這里您可以找到append_df_to_excel()的更新版本，它適用於 Pandas 1.3.0+。

---

這是一個輔助函數：

import os
from openpyxl import load_workbook


def append_df_to_excel(filename, df, sheet_name='Sheet1', startrow=None,
                       truncate_sheet=False, 
                       **to_excel_kwargs):
    """
    Append a DataFrame [df] to existing Excel file [filename]
    into [sheet_name] Sheet.
    If [filename] doesn't exist, then this function will create it.

    @param filename: File path or existing ExcelWriter
                     (Example: '/path/to/file.xlsx')
    @param df: DataFrame to save to workbook
    @param sheet_name: Name of sheet which will contain DataFrame.
                       (default: 'Sheet1')
    @param startrow: upper left cell row to dump data frame.
                     Per default (startrow=None) calculate the last row
                     in the existing DF and write to the next row...
    @param truncate_sheet: truncate (remove and recreate) [sheet_name]
                           before writing DataFrame to Excel file
    @param to_excel_kwargs: arguments which will be passed to `DataFrame.to_excel()`
                            [can be a dictionary]
    @return: None

    Usage examples:

    >>> append_df_to_excel('d:/temp/test.xlsx', df)

    >>> append_df_to_excel('d:/temp/test.xlsx', df, header=None, index=False)

    >>> append_df_to_excel('d:/temp/test.xlsx', df, sheet_name='Sheet2',
                           index=False)

    >>> append_df_to_excel('d:/temp/test.xlsx', df, sheet_name='Sheet2', 
                           index=False, startrow=25)

    (c) [MaxU](https://stackoverflow.com/users/5741205/maxu?tab=profile)
    """
    # Excel file doesn't exist - saving and exiting
    if not os.path.isfile(filename):
        df.to_excel(
            filename,
            sheet_name=sheet_name, 
            startrow=startrow if startrow is not None else 0, 
            **to_excel_kwargs)
        return
    
    # ignore [engine] parameter if it was passed
    if 'engine' in to_excel_kwargs:
        to_excel_kwargs.pop('engine')

    writer = pd.ExcelWriter(filename, engine='openpyxl', mode='a')

    # try to open an existing workbook
    writer.book = load_workbook(filename)
    
    # get the last row in the existing Excel sheet
    # if it was not specified explicitly
    if startrow is None and sheet_name in writer.book.sheetnames:
        startrow = writer.book[sheet_name].max_row

    # truncate sheet
    if truncate_sheet and sheet_name in writer.book.sheetnames:
        # index of [sheet_name] sheet
        idx = writer.book.sheetnames.index(sheet_name)
        # remove [sheet_name]
        writer.book.remove(writer.book.worksheets[idx])
        # create an empty sheet [sheet_name] using old index
        writer.book.create_sheet(sheet_name, idx)
    
    # copy existing sheets
    writer.sheets = {ws.title:ws for ws in writer.book.worksheets}

    if startrow is None:
        startrow = 0

    # write out the new sheet
    df.to_excel(writer, sheet_name, startrow=startrow, **to_excel_kwargs)

    # save the workbook
    writer.save()

使用以下版本進行測試：

• 熊貓 1.2.3
• Openpyxl 3.0.5

Answer 3

隨着openpyxl版本2.4.0和pandas版本0.19.2 ，@ski想出的過程變得簡單一點：

import pandas
from openpyxl import load_workbook

with pandas.ExcelWriter('Masterfile.xlsx', engine='openpyxl') as writer:
    writer.book = load_workbook('Masterfile.xlsx')
    data_filtered.to_excel(writer, "Main", cols=['Diff1', 'Diff2'])
#That's it!

Answer 4

從 pandas 0.24 開始，您可以使用ExcelWriter的mode關鍵字參數簡化此mode ：

import pandas as pd

with pd.ExcelWriter('the_file.xlsx', engine='openpyxl', mode='a') as writer: 
     data_filtered.to_excel(writer) 

Answer 5

我知道這是一個較舊的線程，但這是您在搜索時找到的第一個項目，如果您需要在已創建的工作簿中保留圖表，則上述解決方案不起作用。 在這種情況下，xlwings 是更好的選擇 - 它允許您寫入 Excel 書籍並保留圖表/圖表數據。

簡單的例子：

import xlwings as xw
import pandas as pd

#create DF
months = ['2017-01','2017-02','2017-03','2017-04','2017-05','2017-06','2017-07','2017-08','2017-09','2017-10','2017-11','2017-12']
value1 = [x * 5+5 for x in range(len(months))]
df = pd.DataFrame(value1, index = months, columns = ['value1'])
df['value2'] = df['value1']+5
df['value3'] = df['value2']+5

#load workbook that has a chart in it
wb = xw.Book('C:\\data\\bookwithChart.xlsx')

ws = wb.sheets['chartData']

ws.range('A1').options(index=False).value = df

wb = xw.Book('C:\\data\\bookwithChart_updated.xlsx')

xw.apps[0].quit()

Answer 6

pandas 0.24 中有一個更好的解決方案：

with pd.ExcelWriter(path, mode='a') as writer:
    s.to_excel(writer, sheet_name='another sheet', index=False)

前：

后：

所以現在升級你的熊貓：

pip install --upgrade pandas

Answer 7

老問題，但我猜有些人仍在尋找這個 - 所以......

我覺得這個方法很好，因為所有的工作表都被加載到一個由 Pandas 使用 sheetname=None 選項創建的工作表名稱和數據框對的字典中。 在將電子表格讀入 dict 格式和從 dict 寫回之間添加、刪除或修改工作表很簡單。 對我來說，xlsxwriter 在速度和格式方面比 openpyxl 更適合這項特定任務。

注意：pandas (0.21.0+) 的未來版本會將“sheetname”參數更改為“sheet_name”。

# read a single or multi-sheet excel file
# (returns dict of sheetname(s), dataframe(s))
ws_dict = pd.read_excel(excel_file_path,
                        sheetname=None)

# all worksheets are accessible as dataframes.

# easy to change a worksheet as a dataframe:
mod_df = ws_dict['existing_worksheet']

# do work on mod_df...then reassign
ws_dict['existing_worksheet'] = mod_df

# add a dataframe to the workbook as a new worksheet with
# ws name, df as dict key, value:
ws_dict['new_worksheet'] = some_other_dataframe

# when done, write dictionary back to excel...
# xlsxwriter honors datetime and date formats
# (only included as example)...
with pd.ExcelWriter(excel_file_path,
                    engine='xlsxwriter',
                    datetime_format='yyyy-mm-dd',
                    date_format='yyyy-mm-dd') as writer:

    for ws_name, df_sheet in ws_dict.items():
        df_sheet.to_excel(writer, sheet_name=ws_name)

對於 2013 年問題中的示例：

ws_dict = pd.read_excel('Masterfile.xlsx',
                        sheetname=None)

ws_dict['Main'] = data_filtered[['Diff1', 'Diff2']]

with pd.ExcelWriter('Masterfile.xlsx',
                    engine='xlsxwriter') as writer:

    for ws_name, df_sheet in ws_dict.items():
        df_sheet.to_excel(writer, sheet_name=ws_name)

Answer 8

@MaxU 的解決方案不適用於更新版本的python 和相關包。 它引發錯誤： “zipfile.BadZipFile：文件不是 zip 文件”

我生成了一個新版本的函數，可以很好地與更新版本的 python 和相關包配合使用，並使用 python 進行測試：3.9 | openpyxl: 3.0.6 | 熊貓：1.2.3

此外，我為輔助函數添加了更多功能：

1. 現在它根據單元格內容寬度調整所有列的大小並且所有變量都將可見（參見“resizeColumns”）
2. 您可以處理 NaN，如果您希望 NaN 顯示為 NaN 或空單元格（請參閱“na_rep”）
3. 增加了“startcol”，你可以決定從特定的列開始寫，否則會從col = 0開始

這里的功能：

import pandas as pd

def append_df_to_excel(filename, df, sheet_name='Sheet1', startrow=None, startcol=None,
    truncate_sheet=False, resizeColumns=True, na_rep = 'NA', **to_excel_kwargs):
    """
    Append a DataFrame [df] to existing Excel file [filename]
    into [sheet_name] Sheet.
    If [filename] doesn't exist, then this function will create it.

    Parameters:
      filename : File path or existing ExcelWriter
                 (Example: '/path/to/file.xlsx')
      df : dataframe to save to workbook
      sheet_name : Name of sheet which will contain DataFrame.
                   (default: 'Sheet1')
      startrow : upper left cell row to dump data frame.
                 Per default (startrow=None) calculate the last row
                 in the existing DF and write to the next row...
      truncate_sheet : truncate (remove and recreate) [sheet_name]
                       before writing DataFrame to Excel file

      resizeColumns: default = True . It resize all columns based on cell content width
      to_excel_kwargs : arguments which will be passed to `DataFrame.to_excel()`
                        [can be dictionary]
      na_rep: default = 'NA'. If, instead of NaN, you want blank cells, just edit as follows: na_rep=''


    Returns: None

    *******************

    CONTRIBUTION:
    Current helper function generated by [Baggio]: https://stackoverflow.com/users/14302009/baggio?tab=profile
    Contributions to the current helper function: https://stackoverflow.com/users/4046632/buran?tab=profile
    Original helper function: (c) [MaxU](https://stackoverflow.com/users/5741205/maxu?tab=profile)


    Features of the new helper function:
    1) Now it works with python 3.9 and latest versions of pandas and openpxl
    ---> Fixed the error: "zipfile.BadZipFile: File is not a zip file".
    2) Now It resize all columns based on cell content width AND all variables will be visible (SEE "resizeColumns")
    3) You can handle NaN,  if you want that NaN are displayed as NaN or as empty cells (SEE "na_rep")
    4) Added "startcol", you can decide to start to write from specific column, oterwise will start from col = 0

    *******************



    """
    from openpyxl import load_workbook
    from string import ascii_uppercase
    from openpyxl.utils import get_column_letter
    from openpyxl import Workbook

    # ignore [engine] parameter if it was passed
    if 'engine' in to_excel_kwargs:
        to_excel_kwargs.pop('engine')

    try:
        f = open(filename)
        # Do something with the file
    except IOError:
        # print("File not accessible")
        wb = Workbook()
        ws = wb.active
        ws.title = sheet_name
        wb.save(filename)

    writer = pd.ExcelWriter(filename, engine='openpyxl', mode='a')


    # Python 2.x: define [FileNotFoundError] exception if it doesn't exist
    try:
        FileNotFoundError
    except NameError:
        FileNotFoundError = IOError


    try:
        # try to open an existing workbook
        writer.book = load_workbook(filename)

        # get the last row in the existing Excel sheet
        # if it was not specified explicitly
        if startrow is None and sheet_name in writer.book.sheetnames:
            startrow = writer.book[sheet_name].max_row

        # truncate sheet
        if truncate_sheet and sheet_name in writer.book.sheetnames:
            # index of [sheet_name] sheet
            idx = writer.book.sheetnames.index(sheet_name)
            # remove [sheet_name]
            writer.book.remove(writer.book.worksheets[idx])
            # create an empty sheet [sheet_name] using old index
            writer.book.create_sheet(sheet_name, idx)

        # copy existing sheets
        writer.sheets = {ws.title:ws for ws in writer.book.worksheets}
    except FileNotFoundError:
        # file does not exist yet, we will create it
        pass

    if startrow is None:
        # startrow = -1
        startrow = 0

    if startcol is None:
        startcol = 0

    # write out the new sheet
    df.to_excel(writer, sheet_name, startrow=startrow, startcol=startcol, na_rep=na_rep, **to_excel_kwargs)


    if resizeColumns:

        ws = writer.book[sheet_name]

        def auto_format_cell_width(ws):
            for letter in range(1,ws.max_column):
                maximum_value = 0
                for cell in ws[get_column_letter(letter)]:
                    val_to_check = len(str(cell.value))
                    if val_to_check > maximum_value:
                        maximum_value = val_to_check
                ws.column_dimensions[get_column_letter(letter)].width = maximum_value + 2

        auto_format_cell_width(ws)

    # save the workbook
    writer.save()

示例用法：

# Create a sample dataframe
df = pd.DataFrame({'numbers': [1, 2, 3],
                    'colors': ['red', 'white', 'blue'],
                    'colorsTwo': ['yellow', 'white', 'blue'],
                    'NaNcheck': [float('NaN'), 1, float('NaN')],
                    })

# EDIT YOUR PATH FOR THE EXPORT 
filename = r"C:\DataScience\df.xlsx"   

# RUN ONE BY ONE IN ROW THE FOLLOWING LINES, TO SEE THE DIFFERENT UPDATES TO THE EXCELFILE 
  
append_df_to_excel(filename, df, index=False, startrow=0) # Basic Export of df in default sheet (Sheet1)
append_df_to_excel(filename, df, sheet_name="Cool", index=False, startrow=0) # Append the sheet "Cool" where "df" is written
append_df_to_excel(filename, df, sheet_name="Cool", index=False) # Append another "df" to the sheet "Cool", just below the other "df" instance
append_df_to_excel(filename, df, sheet_name="Cool", index=False, startrow=0, startcol=5) # Append another "df" to the sheet "Cool" starting from col 5
append_df_to_excel(filename, df, index=False, truncate_sheet=True, startrow=10, na_rep = '') # Override (truncate) the "Sheet1", writing the df from row 10, and showing blank cells instead of NaN

Answer 9

def append_sheet_to_master(self, master_file_path, current_file_path, sheet_name):
    try:
        master_book = load_workbook(master_file_path)
        master_writer = pandas.ExcelWriter(master_file_path, engine='openpyxl')
        master_writer.book = master_book
        master_writer.sheets = dict((ws.title, ws) for ws in master_book.worksheets)
        current_frames = pandas.ExcelFile(current_file_path).parse(pandas.ExcelFile(current_file_path).sheet_names[0],
                                                               header=None,
                                                               index_col=None)
        current_frames.to_excel(master_writer, sheet_name, index=None, header=False)

        master_writer.save()
    except Exception as e:
        raise e

這工作得很好，唯一的問題是主文件（我們添加新工作表的文件）的格式丟失了。

Answer 10

writer = pd.ExcelWriter('prueba1.xlsx'engine='openpyxl',keep_date_col=True)

“keep_date_col”希望對你有幫助

Answer 11

book = load_workbook(xlsFilename)
writer = pd.ExcelWriter(self.xlsFilename)
writer.book = book
writer.sheets = dict((ws.title, ws) for ws in book.worksheets)
df.to_excel(writer, sheet_name=sheetName, index=False)
writer.save()

Answer 12

方法：

• 如果不存在，可以創建文件
• 根據工作表名稱附加到現有的 excel

import pandas as pd
from openpyxl import load_workbook

def write_to_excel(df, file):
    try:
        book = load_workbook(file)
        writer = pd.ExcelWriter(file, engine='openpyxl') 
        writer.book = book
        writer.sheets = dict((ws.title, ws) for ws in book.worksheets)
        df.to_excel(writer, **kwds)
        writer.save()
    except FileNotFoundError as e:
        df.to_excel(file, **kwds)

用法：

df_a = pd.DataFrame(range(10), columns=["a"])
df_b = pd.DataFrame(range(10, 20), columns=["b"])
write_to_excel(df_a, "test.xlsx", sheet_name="Sheet a", columns=['a'], index=False)
write_to_excel(df_b, "test.xlsx", sheet_name="Sheet b", columns=['b'])

Answer 13

@MaxU 的解決方案效果很好。 我只有一個建議：

如果指定了 truncate_sheet=True，則不應從現有工作表中保留“startrow”。 我建議：

        if startrow is None and sheet_name in writer.book.sheetnames:
            if not truncate_sheet: # truncate_sheet would use startrow if provided (or zero below)
                startrow = writer.book[sheet_name].max_row

Answer 14

我使用了這里描述的答案

from openpyxl import load_workbook
writer = pd.ExcelWriter(p_file_name, engine='openpyxl', mode='a')
writer.book = load_workbook(p_file_name)
writer.sheets = {ws.title:ws for ws in writer.book.worksheets}
df.to_excel(writer, 'Data', startrow=10, startcol=20)
writer.save()

Answer 15

我建議使用 xlwings ( https://docs.xlwings.org/en/stable/api.html )，它對這個應用程序非常強大......這就是我使用它的方式：

import xlwings as xw
import pandas as pd
import xlsxwriter

# function to get the active workbook
def getActiveWorkbook():
    try:
        # logic from xlwings to grab the current excel file
        activeWb = xw.books.active
    except:
        # print error message if unable to get the current workbook
        print('Unable to grab the current Workbook')
        pause()
        exitProgram()
    else:
        return activeWb

# function that returns the last row number and last cell of a sheet
def getLastRow(myBook, sheetName):
    lastRow = myBook.sheets[sheetName].range("A1").current_region.last_cell.row
    lastCol = str(xlsxwriter.utility.xl_col_to_name(myBook.sheets[sheetName].range("A1").current_region.last_cell.column))
    return str(lastRow), lastCol + str(lastRow)

activeWb = getActiveWorkbook()
df = pd.DataFrame(data=[1,2,3])

# look at worksheet = Part Number Status
sheetName = "Sheet1"
ws = activeWb.sheets[sheetName]
lastRow, lastCell = getLastRow(activeWb, sheetName)
if int(lastRow) > 1:
    ws.range("A1:" + lastCell).clear()
ws.range("A1").options(index=False, header=False).value = df.fillna('')

這似乎對我的應用程序非常有效，因為 .xlsm 工作簿可能非常棘手。 您可以將其作為 python 腳本執行，也可以使用 pyinstaller 將其轉換為可執行文件，然后通過 excel 宏運行.exe。 您還可以使用 xlwings 從 Python 調用 VBA 宏，這非常有用。

Answer 16

通過使用 pandas.DataFrame.to_excel() 方法並將模式參數指定為“a”（追加模式），您可以寫入現有的 Excel 文件，而不會使用 pandas 覆蓋數據。

這是一個例子：

import pandas as pd

# Create a sample DataFrame
df = pd.DataFrame({'A': [1, 2, 3], 'B': [4, 5, 6], 'C': [7, 8, 9]})

# Write the DataFrame to an existing Excel file in append mode
df.to_excel('existing_file.xlsx', engine='openpyxl', mode='a', index=False, sheet_name='Sheet1')