Is it possible to overwrite existing data in .xlsx file with openpyxl? - python

Say I want to update som data in example1.xlsx.
Is this possible to do using openpyxl without having to save it as a new file?

As far as I can tell you can open a workbook with openpyxl, modify some data, then save the workbook in place:
wb = openpyxl.load_workbook('path\\to\\workbook.xlsx')
c = wb['Sheet1']['A1']
c.value = 'hello'
wb.save('path\\to\\workbook.xlsx')
If you're saying that your workbook is too big to manipulate in this way, it looks as if you would have to open it in read-only mode, manipulate the data as you read it in, and write it to a new workbook in write-only mode.

Related

how to add the worksheet object in openpyxl to the new sheet of the existing xlsx document

I have done a lot of research and failed to solve this problem, so I am coming here to ask for help. I read the worksheet object from a file below,
sheet_2_workbook = openpyxl. load_workbook(sheet_2_path)
sheet_2 = sheet_2_workbook.worksheets\[0\]
As described in the title, I want to add it to the new sheet of the existing .xlsx document, how should I do it?
I tried to realize this as below, but the new document obtained by this method will lose some of the original formatting, including the cell background color and merged cells
old_wb = openpyxl. load_workbook(file_list[i])
old_sheet_name = old_wb. get_sheet_names()[0]
old_ws = old_wb[old_sheet_name]
ws2 = combined_wb.create_sheet(sheet_name)
for row in old_ws.values:
ws2.append(row)
I am sure that the worksheet object read in the file contains these formats, because the .xlsx document I dumped with the following code has the format mentioned above
sheet_2_workbook. save(filename = temp_save_path)
How I would go about your task of adding a worksheet object to a new sheet in an existing Excel document using openpyxl:
Import the openpyxl module
Load the existing Excel document using the load_workbook() function
Create a new sheet using the create_sheet() method of the Workbook object
Alternatively, you can specify the name of the new sheet as a string when calling the create_sheet() method
Save changes using the save() method
(To preserve the formatting you can use the copy_worksheet() to create a copy of the original worksheet and add it to the workbook)
import openpyxl
workbook = openpyxl.load_workbook('existing_document.xlsx')
sheet_2_workbook = openpyxl.load_workbook(sheet_2_path)
sheet_2 = sheet_2_workbook.worksheets[0]
new_sheet = workbook.copy_worksheet(sheet_2)
// Alternatively, you can specify the name of the new sheet as a string
// new_sheet = workbook.copy_worksheet(sheet_2, 'Sheet2')
workbook.save('existing_document.xlsx')

Is it possible to append data to an xls file in Python?

I am trying to add a large dataset to an existing xls spreadsheet.
I'm currently writing to it using a pandas dataframe and the .to_excel() function, however this erases the existing data in the (multi-sheet) workbook. The existing spreadsheet is very large and complex,it also interacts with several other files, so I can't convert it to xlsx or read and rewrite all of the data, as I've seen some suggestions on other questions. I want the data that I am adding to be pasted starting from a set row in an existing sheet.
Yes , you can use the library xlsxwriter , link= https://xlsxwriter.readthedocs.io
code example :
import xlsxwriter
Name="MyFile"+".xlsx"
workbook = xlsxwriter.Workbook(Name)
worksheet = workbook.add_worksheet()
worksheet.write("A1", "Incident category".decode("utf-8"))
worksheet.write("B1", "Longitude".decode("utf-8"))
worksheet.write("C1", "Latitude".decode("utf-8"))
workbook.close()

Python - save new Excel sheet with existing format

I want to save excel sheet with existing sheet formats and background color.
I could save successfully to a new file with out old file format.
How can I keep the existing excel sheet format when save in to a new file.
writer = pd.ExcelWriter('New.xlsx', engine='xlsxwriter')
dfDiff.to_excel(writer, sheet_name='DIFF', index=False)
writer.save()
I had no good experience with pandas and format styles... what works if you use win32com like this example:
from win32com.client import DispatchEx
excel = DispatchEx('Excel.Application')
wbP=excel.Workbooks.Open(r'C:\Temp\Junk\Temp.xlsx')
wbG=excel.Workbooks.Open(r'C:\Temp\Junk\Temp2.xlsx')
wbG.Worksheets('TAA2').Copy(Before=wbP.Worksheets("TAA"))
wbP.SaveAs(r'C:\Temp\Junk\Temp.xlsx')
excel.Quit()
del excel # ensure Excel process ends
this copies everything... (styles, formats, formulas etc.)
Another option is copy the whole workbook and delete the not needed sheets, if you create a new file and not editing an existing one...
Copy worksheet from one workbook to another one using Openpyxl

xlsx get_worksheet_by_name return none?

I have my code like this :
import xlsxwriter
workbook = xlsxwriter.Workbook('result.xlsx')
sheet = workbook.get_worksheet_by_name('result')
but sheet always be None
I have checked my result.xlsx.I'm sure result.xlsx have 'result' sheet.
Why?
xlsxwriter, as the name suggests, can't read xlsx files but only write them. By doing this xlsxwriter.Workbook('result.xlsx') you create a new python object, but you're not actually reading or writing that file on your hard drive.
As Joost answered, xlsxwriter can't read xlsx files but only write them. Maybe you could use codes below to instead:
data = openpyxl.load_workbook('result.xlsx')
sheet = data['result']

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

I'm able to open my pre-existing workbook, but I don't see any way to open pre-existing worksheets within that workbook. Is there any way to do this?
You cannot append to an existing xlsx file with xlsxwriter.
There is a module called openpyxl which allows you to read and write to preexisting excel file, but I am sure that the method to do so involves reading from the excel file, storing all the information somehow (database or arrays), and then rewriting when you call workbook.close() which will then write all of the information to your xlsx file.
Similarly, you can use a method of your own to "append" to xlsx documents. I recently had to append to a xlsx file because I had a lot of different tests in which I had GPS data coming in to a main worksheet, and then I had to append a new sheet each time a test started as well. The only way I could get around this without openpyxl was to read the excel file with xlrd and then run through the rows and columns...
i.e.
cells = []
for row in range(sheet.nrows):
cells.append([])
for col in range(sheet.ncols):
cells[row].append(workbook.cell(row, col).value)
You don't need arrays, though. For example, this works perfectly fine:
import xlrd
import xlsxwriter
from os.path import expanduser
home = expanduser("~")
# this writes test data to an excel file
wb = xlsxwriter.Workbook("{}/Desktop/test.xlsx".format(home))
sheet1 = wb.add_worksheet()
for row in range(10):
for col in range(20):
sheet1.write(row, col, "test ({}, {})".format(row, col))
wb.close()
# open the file for reading
wbRD = xlrd.open_workbook("{}/Desktop/test.xlsx".format(home))
sheets = wbRD.sheets()
# open the same file for writing (just don't write yet)
wb = xlsxwriter.Workbook("{}/Desktop/test.xlsx".format(home))
# run through the sheets and store sheets in workbook
# this still doesn't write to the file yet
for sheet in sheets: # write data from old file
newSheet = wb.add_worksheet(sheet.name)
for row in range(sheet.nrows):
for col in range(sheet.ncols):
newSheet.write(row, col, sheet.cell(row, col).value)
for row in range(10, 20): # write NEW data
for col in range(20):
newSheet.write(row, col, "test ({}, {})".format(row, col))
wb.close() # THIS writes
However, I found that it was easier to read the data and store into a 2-dimensional array because I was manipulating the data and was receiving input over and over again and did not want to write to the excel file until it the test was over (which you could just as easily do with xlsxwriter since that is probably what they do anyway until you call .close()).
After searching a bit about the method to open the existing sheet in xlxs, I discovered
existingWorksheet = wb.get_worksheet_by_name('Your Worksheet name goes here...')
existingWorksheet.write_row(0,0,'xyz')
You can now append/write any data to the open worksheet.
You can use the workbook.get_worksheet_by_name() feature:
https://xlsxwriter.readthedocs.io/workbook.html#get_worksheet_by_name
According to https://xlsxwriter.readthedocs.io/changes.html the feature has been added on May 13, 2016.
"Release 0.8.7 - May 13 2016
-Fix for issue when inserting read-only images on Windows. Issue #352.
-Added get_worksheet_by_name() method to allow the retrieval of a worksheet from a workbook via its name.
-Fixed issue where internal file creation and modification dates were in the local timezone instead of UTC."
Although it is mentioned in the last two answers with it's documentation link, and from the documentation it seems indeed there are new methods to work with the "worksheets", I couldn't able to find this methods in the latest package of "xlsxwriter==3.0.3"
"xlrd" has removed support for anything other than xls files now.
Hence I was able to workout with "openpyxl" this gives you the expected functionality as mentioned in the first answer above.

Categories

Resources