Updating excel sheet with Pandas without overwriting the file

Question

I am trying to update an excel sheet with Python codes. I read specific cell and update it accordingly but Padadas overwrites the entire excelsheet which I loss other pages as well as formatting. Anyone can tell me how I can avoid it?

       Record = pd.read_excel("Myfile.xlsx", sheet_name'Sheet1', index_col=False)
       Record.loc[1, 'WORDS'] = int(self.New_Word_box.get())
       Record.loc[1, 'STATUS'] = self.Stat.get()
       Record.to_excel("Myfile.xlsx", sheet_name='Student_Data', index =False)

My code are above, as you can see, I only want to update few cells but it overwrites the entire excel file. I tried to search for answer but couldn't find any specific answer.

Appreciate your help.

Answer 1

Update: Added more clarifications

Steps:

1) Read the sheet which needs changes in a dataframe and make changes in that dataframe.

2) Now the changes are reflected in the dataframe but not in the sheet. Use the following function with the dataframe in step 1 and name of the sheet to be modified. You will use the truncate_sheet param to completely replace the sheet of concern. The function call would be like so:

append_df_to_excel(filename, df, sheet_name, startrow=0, truncate_sheet=True)

from openpyxl import load_workbook
import pandas as pd

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.

    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
      to_excel_kwargs : arguments which will be passed to `DataFrame.to_excel()`
                        [can be dictionary]

    Returns: None
    """
    # ignore [engine] parameter if it was passed
    if "engine" in to_excel_kwargs:
        to_excel_kwargs.pop("engine")

    writer = pd.ExcelWriter(filename, engine="openpyxl")

    # Python 2.x: define [FileNotFoundError] exception if it doesn"t exist
    try:
        FileNotFoundError
    except NameError:
        FileNotFoundError = IOError

    if "index" not in to_excel_kwargs:
        to_excel_kwargs["index"] = False

    try:
        # try to open an existing workbook
        if "header" not in to_excel_kwargs:
            to_excel_kwargs["header"] = True
        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
            to_excel_kwargs["header"] = False

        # 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
        to_excel_kwargs["header"] = True

    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()

We can't replace openpyxl engine here to write excel files as asked in comment. Refer reference 2.

References:

1) https://stackoverflow.com/a/38075046/6741053

2) xlsxwriter: is there a way to open an existing worksheet in my workbook?