Replacing data in xlsx sheet with pandas dataframe

Question

I have an xlsx file with multiple tabs, one of them being Town_names that already has some data in it.

I’d like to overwrite that data with a dataframe – Town_namesDF – while keeping the rest of the xlsx tabs intact.

I’ve tried the following:

with pd.ExcelWriter(r'path/to/file.xlsx', engine='openpyxl', mode='a') as writer:
    Town_namesDF.to_excel(writer,sheet_name='Town_names')
    writer.save()

writer.close()

But it ends up creating a new tab Town_names1 instead of overwriting the Town_names tab. Am I missing something? Thanks.

Asked By: Robert C

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Source

Answer 1

You could try this to store all of the other sheets temporarily and then add them back. I don’t think this would save any formulas or formatting though.

Store_sheet1=pd.read_excel('path/to/file.xlsx',sheetname='Sheet1')
Store_sheet2=pd.read_excel('path/to/file.xlsx',sheetname='Sheet2')
Store_sheet3=pd.read_excel('path/to/file.xlsx',sheetname='Sheet3')

with pd.ExcelWriter(r'path/to/file.xlsx', engine='openpyxl', mode='a') as writer:
    Town_namesDF.to_excel(writer,sheet_name='Town_names')
    Store_sheet1.to_excel(writer,sheet_name='Sheet1')
    Store_sheet2.to_excel(writer,sheet_name='Sheet2')
    Store_sheet3.to_excel(writer,sheet_name='Sheet3')
writer.save()
writer.close()

Answered By: MBA Coder

Answer 2

Since you want to overwrite, but there is no direct option for that(like in julia’s XLSX there is option for cell_ref). Simply delete the duplicate if it exists and then write.

with pd.ExcelWriter('/path/to/file.xlsx',engine = "openpyxl",  mode='a') as writer:
 workBook = writer.book
 try:
  workBook.remove(workBook['Town_names'])
 except:
  print("worksheet doesn't exist")
 finally:
  df.to_excel(writer, sheet_name='Town_names')
 writer.save()

Answered By: Yugandhar

Answer 3

Well, I’ve managed to do this. This is not a clean solution and not fast at all, but I’ve made use of openpyxl documentation for working with pandas found here: https://openpyxl.readthedocs.io/en/latest/pandas.html

I’m effectively selecting the Town_names sheet, clearing it with ws.delete_rows() and then appending each row of my dataframe to the sheet.

wb = openpyxl.load_workbook(r'path/to/file.xlsx')
ws = wb.get_sheet_by_name('Town_names')
ws.delete_rows(0, 1000)

wb.save(r'path/to/file.xlsx')

wb = openpyxl.load_workbook(r'path/to/file.xlsx')
activeSheet = wb.get_sheet_by_name('Town_names')

for r in dataframe_to_rows(Town_namesDF, index=False, header=True):
    activeSheet.append(r)

for cell in activeSheet['A'] + activeSheet[1]:
    cell.style = 'Pandas'

wb.save(r'path/to/file.xlsx')

A bit messy and I hope there’s a better solution than mine, but this worked for me.

Answered By: Robert C

Answer 4

Hi you could use xlwings for that task. Here is an example.

import xlwings as xw
import pandas as pd

filename = "test.xlsx"
df = pd.read_excel(filename, "Town_names")

# Do your modifications of the worksheet here. For example, the following line "df * 2".
df = df * 2 

app = xw.App(visible=False)
wb = xw.Book(filename)
ws = wb.sheets["Town_names"]

ws.clear()
ws["A1"].options(pd.DataFrame, header=1, index=False, expand='table').value = df

# If formatting of column names and index is needed as xlsxwriter does it, the following lines will do it.
ws["A1"].expand("right").api.Font.Bold = True
ws["A1"].expand("down").api.Font.Bold = True
ws["A1"].expand("right").api.Borders.Weight = 2
ws["A1"].expand("down").api.Borders.Weight = 2

wb.save(filename)
app.quit()

Answered By: mouwsy

Answer 5

since pandas version 1.3.0. there is a new parameter: "if_sheet_exists"
{‘error’, ‘new’, ‘replace’}

pd.ExcelWriter(r'path/to/file.xlsx', engine='openpyxl', mode='a', if_sheet_exists='replace')

Answered By: JorgeBB

Replacing data in xlsx sheet with pandas dataframe

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