I am unable to find examples where xlwt is used to write into existing files. I have a existing xls file that I need to write to. When I use xlrd to read the file, I cant seem to figure out how to transform the "Book" type returned into a xlwt.Workbook. I would appreciate if someone can point me to an example.
5 Answers
Here's some sample code I used recently to do just that.
It opens a workbook, goes down the rows, if a condition is met it writes some data in the row. Finally it saves the modified file.
from xlutils.copy import copy # http://pypi.python.org/pypi/xlutils
from xlrd import open_workbook # http://pypi.python.org/pypi/xlrd
START_ROW = 297 # 0 based (subtract 1 from excel row number)
col_age_november = 1
col_summer1 = 2
col_fall1 = 3
rb = open_workbook(file_path,formatting_info=True)
r_sheet = rb.sheet_by_index(0) # read only copy to introspect the file
wb = copy(rb) # a writable copy (I can't read values out of this, only write to it)
w_sheet = wb.get_sheet(0) # the sheet to write to within the writable copy
for row_index in range(START_ROW, r_sheet.nrows):
age_nov = r_sheet.cell(row_index, col_age_november).value
if age_nov == 3:
#If 3, then Combo I 3-4 year old for both summer1 and fall1
w_sheet.write(row_index, col_summer1, 'Combo I 3-4 year old')
w_sheet.write(row_index, col_fall1, 'Combo I 3-4 year old')
wb.save(file_path + '.out' + os.path.splitext(file_path)[-1])
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60this should have been the accepted answer – chefsmart Mar 29 '11 at 13:35
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55@chefsmart Yup, it should have been. Also, Greg answered without being a dick. +1 – RaytheonLiszt Jan 12 '12 at 01:49
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11Does not this program silently throw away everything it cannot translate: VB macros, most of graphics, advanced formatting and page layouts ? – jmster Dec 18 '14 at 08:49
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1Yes it appears it does. I tested it and it throwed away my formatting. – Viliam Nov 08 '17 at 13:05
You need xlutils.copy
. Try something like this:
from xlutils.copy import copy
w = copy('book1.xls')
w.get_sheet(0).write(0,0,"foo")
w.save('book2.xls')
Keep in mind you can't overwrite cells by default as noted in this question.
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2I get an error: AttributeError: 'str' object has no attribute 'formatting_info' Do you know why this is so? – Josh May 21 '13 at 17:40
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The code example is exactly this:
from xlutils.copy import copy
from xlrd import *
w = copy(open_workbook('book1.xls'))
w.get_sheet(0).write(0,0,"foo")
w.save('book2.xls')
You'll need to create book1.xls to test, but you get the idea.

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openpyxl
# -*- coding: utf-8 -*-
import openpyxl
file = 'sample.xlsx'
wb = openpyxl.load_workbook(filename=file)
# Seleciono la Hoja
ws = wb.get_sheet_by_name('Hoja1')
# Valores a Insertar
ws['A3'] = 42
ws['A4'] = 142
# Escribirmos en el Fichero
wb.save(file)
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2Although this code might solve the problem, you should always explain what it does and why it helps. – BDL Apr 18 '17 at 13:35
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This doesn't work for `.xls` format which the primary reason of using this library in 2023 – dhiraj suvarna Jun 17 '23 at 16:02
I had the same problem. My customer ordered me Python 3.4 script that updates XLS (not XLSX) Excel files.
The 1st package xlrd was installed by "pip install" without problems in my Python home.
The 2nd one xlwt needed to say "pip install xlwt-future" to be compatible.
The 3rd one xlutils has no support for Python 3, but I adapted it a little bit and now it works at least for dummy script:
#!C:\Python343\python
from xlutils.copy import copy # http://pypi.python.org/pypi/xlutils
from xlrd import open_workbook # http://pypi.python.org/pypi/xlrd
from xlwt import easyxf # http://pypi.python.org/pypi/xlwt
file_path = 'C:\Dev\Test_upd.xls'
rb = open_workbook('C:\Dev\Test.xls',formatting_info=True)
r_sheet = rb.sheet_by_index(0) # read only copy to introspect the file
wb = copy(rb) # a writable copy (I can't read values out of this, only write to it)
w_sheet = wb.get_sheet(0) # the sheet to write to within the writable copy
w_sheet.write(1, 1, 'Value')
wb.save(file_path)
I attached the file here: http://ifolder.su/43507580
Write to alexander.samoylov@gmail.com if it got expired.
P.S.: Some functions are not called in the dummy example, so maybe they will need for an adaptation also. Who wants to do it, fix exceptions one-by-one with a google help. It's not a very difficult task, because the package code is small...

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