Django : python pandas generating blank excel - django

Question

I am using pandas tool to create downloadable excel file.Excel will get it data from SQL table , which in turn will get populated depending on values entered by user.I have attached one download button in my web page to download the excel.
On clicking download button it's generating a blank excel file with sheet name and file name as Consistency Report. Can anyone point out what I am doing wrong here.
Thanks in advance
views.py
def export_excel(request):
response = HttpResponse(content_type="application/vnd.ms-excel")
response['Content-Disposition'] = 'attachment; filename=Consistency Report.xls'
fname = 'Consistency Report.xls'
cnxn = pyodbc.connect('DRIVER={SQL Server Native Client 10.0};SERVER=******;DATABASE=testing;UID=***;PWD=******')
cursor = cnxn.cursor()
cursor.execute("select * from dhm_consis_report_tbl")
columns = [column[0] for column in cursor.description]
data=cursor.fetchall()
cursor.commit()
print(columns)
for i in range(0,len(data)):
data[i]=tuple(data[i])
df = ps.DataFrame(data=data,columns=columns)
writer = ps.ExcelWriter('Consistency Report.xls',engine='xlwt')
df.to_excel(writer,sheet_name='Report')
writer.save()
return response
So, I edited my views.py and am able to generate and download excel file but the problem is that the file is now downloading at two locations; one at my project folder and one at my download folder.Also the file at download folder is empty while the one at my project folder contains data.Can anybody explain why this is happening?
Modified views.py
def export_excel(request):
response = HttpResponse(content_type="application/vnd.ms-excel;charset=utf-8")
response['Content-Disposition'] = 'attachment; filename=Consistency Report.xls'
df = ps.DataFrame.from_records(DHM_Consis_Report.objects.values('conquery_source','conquery_name','conquery_count','conquery_desc','criticality','sp_status','con_rundate','instance_id'))
print(df)
writer = ps.ExcelWriter('Consistency Report.xls',encoding='utf-8')
df.to_excel(writer,sheet_name='Report')
writer.save()
return response

Answer 1

Finally, I was able to generate required excel.Earlier I was creating and writing the excel with data but my HttpResponse was not getting the required data.I put the logic regarding generating excel in separate function and logic regarding downloading the generated file in separate function.This is what I did.
I know it's crude and inefficient but this works for me.If anyone has better way to do this please share.
views.py
#login_required
def consisreports(request):
cust= customername
username=None
if request.user.is_authenticated():
username=request.user.username
print(username)
table=ConsisReport(DHM_Consis_Report.objects.all())
RequestConfig(request,paginate={"per_page": 25}).configure(table)
todays=date.today()
todays=todays.strftime("%d-%m-%y")
filename="Consistency Report %s as on %s %s.xls"%(cust,str(todays),username)
colname=['Customer','Query ','Count','Desc','Criticality','Status','Rundate','Instance ID']
df = ps.DataFrame.from_records(DHM_Consis_Report.objects.values('conquery_source','conquery_name','conquery_count','conquery_desc','criticality','sp_status','con_rundate','instance_id'))
df=df[['conquery_source','conquery_name','conquery_count','conquery_desc','criticality','sp_status','con_rundate','instance_id']]
print(df)
#df.save('C:/Users/P1097/Desktop')
writer = ps.ExcelWriter(filename)
df.to_excel(writer,sheet_name='Report',index=False,engine='xlsxwriter',header=colname)
writer.save()
return render(request, 'consistency/consresult.html', {'table': table,'customername':cust})
#login_required
def export_excel(request):
custname=customername
username=None
if request.user.is_authenticated():
username=request.user.username
todays=date.today()
todays=todays.strftime("%d-%m-%y")
filename="Consistency Report %s as on %s %s.xls"%(custname,str(todays),username)
wrapper=open(filename,"rb")
cont=wrapper.read()
response = HttpResponse(cont,content_type="application/vnd.ms-excel;charset=utf-8")
response['Content-Length']=os.path.getsize(filename)
size=os.path.getsize(filename)
print(size)
wrapper.close()
response['Content-Disposition'] = 'attachment; filename= %s'%filename
return response