Struggling for this for hours so I decided to ask for help from experts here:
I want to modify existing excel sheet without overwriting content. I have other sheets in this excel file and I don't want to impact other sheets.
I've created sample code, not sure how to add the second sheet that I want to keep though.
t=pd.date_range('2004-01-31', freq='M', periods=4)
first=pd.DataFrame({'A':[1,1,1,1],
'B':[2,2,2,2]}, index=t)
first.index=first.index.strftime('%Y-%m-%d')
writer=pd.ExcelWriter('test.xlsx')
first.to_excel(writer, sheet_name='Here')
first.to_excel(writer, sheet_name='Keep')
#how to update the sheet'Here', cell A5:C6 with following without overwriting the rest?
#I want to keep the sheet "Keep"
update=pd.DataFrame({'A':[3,4],
'B':[4,5]}, index=pd.date_range('2004-04-30',
periods=2,
freq='M'))
I've researched SO. But not sure how to write a dataframe into the sheet.
Example I've tried:
import openpyxl
xfile = openpyxl.load_workbook('test.xlsx')
sheet = xfile.get_sheet_by_name('test')
sheet['B5']='wrote!!'
xfile.save('test2.xlsx')
Figured it out by myself:
#Prepare the excel we want to write to
t=pd.date_range('2004-01-31', freq='M', periods=4)
first=pd.DataFrame({'A':[1,1,1,1],
'B':[2,2,2,2]}, index=t)
first.index=first.index.strftime('%Y-%m-%d')
writer=pd.ExcelWriter('test.xlsx')
first.to_excel(writer, sheet_name='Here')
first.to_excel(writer, sheet_name='Keep')
#read the existing sheets so that openpyxl won't create a new one later
book = load_workbook('test.xlsx')
writer = pandas.ExcelWriter('test.xlsx', engine='openpyxl')
writer.book = book
writer.sheets = dict((ws.title, ws) for ws in book.worksheets)
#update without overwrites
update=pd.DataFrame({'A':[3,4],
'B':[4,5]}, index=(pd.date_range('2004-04-30',
periods=2,
freq='M').strftime('%Y-%m-%d')))
update.to_excel(writer, "Here", startrow=1, startcol=2)
writer.save()