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How to allow users to download an excel file using python/Flask?

I have a method that takes in an excel file, read the excel file, extracts data from it and save. The issue I am having now is how to write a method that returns the excel file and allow users to download it from the frontend.
This is the main file
class UploadFileForm(FlaskForm):
file = FileField('File', validators=[InputRequired()])
submit = SubmitField('Download File')
#app.route('/', methods=['GET', 'POST'])
def home_api():
form = UploadFileForm()
if form.validate_on_submit():
file = form.file.data
file.save(os.path.join(os.path.abspath(os.path.dirname(_file_)),app.config['UPLOAD_FOLDER'],secure_filename(file.filename)))
process_xl(os.path.join(os.path.abspath(os.path.dirname(_file_)),app.config['UPLOAD_FOLDER'],secure_filename(file.filename)))
download_file(os.path.join(os.path.abspath(os.path.dirname(_file_)),app.config['UPLOAD_FOLDER'],secure_filename(file.filename)))
return 'File has been uploaded'
return render_template('index.html', form=form)
This is the service that does the extraction and little manipulation.
from flask import send_file
import requests
from openpyxl import load_workbook
def weather(city):
url = "https://community-open-weather-map.p.rapidapi.com/weather"
querystring = {"q":f"{city}","lat":"0","lon":"0","callback":"test","id":"2172797","lang":"null","units":"imperial","mode":"HTML"}
headers = {
"X-RapidAPI-Key": "0a109dce92msh070cc32fb93c003p1e4e8djsnef8cf195fed1",
"X-RapidAPI-Host": "community-open-weather-map.p.rapidapi.com"
}
response = requests.request("GET", url, headers=headers, params=querystring)
return response.text
def process_xl(filename):
wb = load_workbook(filename=filename)
sheet_1 = wb['Sheet1']
sheet_2 = wb['Sheet2']
city_1 = sheet_1['A1'].value
city_2 = sheet_2['']
Based on the requirement, I need a function that will return the excel file which I can call in the main method. I have tried returning the the excel file it was not working

You only need to create a route that sends the file to the client
here is how
import os
from flask import send_file
#app.route('/downlaod')
def downloadExcel():
root_path = "path_to_your_file"
filename = "your_file_name.xlsx"
file_path = os.path.join(root_path, filename)
return send_file(file_path)
You function should save the file.
def process_xl(filename):
wb = load_workbook(filename=filename)
sheet_1 = wb['Sheet1']
sheet_2 = wb['Sheet2']
city_1 = sheet_1['A1'].value
city_2 = sheet_2['']
wb.save(filename)

This line solved my problem
return send_from_directory('directory-path', file.filename)
This is the full code here
from flask import send_from_directory
class UploadFileForm(FlaskForm):
file = FileField('File', validators=[InputRequired()])
submit = SubmitField('Download File')
#app.route('/', methods=['GET', 'POST'])
def home_api():
form = UploadFileForm()
if form.validate_on_submit():
file = form.file.data
file.save(os.path.join(os.path.abspath(os.path.dirname(_file_)),app.config['UPLOAD_FOLDER'],secure_filename(file.filename)))
process_xl(os.path.join(os.path.abspath(os.path.dirname(_file_)),app.config['UPLOAD_FOLDER'],secure_filename(file.filename)))
download_file(os.path.join(os.path.abspath(os.path.dirname(_file_)),app.config['UPLOAD_FOLDER'],secure_filename(file.filename)))
return send_from_directory('directory-path', file.filename)
return render_template('index.html', form=form)

How does one write Python code that merges 2 files created using wkhtmltopdf into 1 pdf file using pypdf2

I have an application with the back-end written in Python that converts html files to pdf files. To do this it implements wkhtmltopdf (https://wkhtmltopdf.org/). It currently works perfectly for creating a single PDF file from an html file and outputs that to the user.
However, I need to be able to create multiple separate PDF files and then merge the files together into a single PDF.
I have been trying to do this using Pypdf2 with the PdfFileMerger() function (https://pythonhosted.org/PyPDF2/PdfFileMerger.html) and haven't been able to do it. I keep getting 'bytes' object has no attribute 'seek'
Here is my current code:
def multi_test_sheet(request, equipment_id):
if not request.user.is_authenticated:
return render(request, "jobs/login.html", {"message": None})
from io import BytesIO
from PyPDF2 import PdfFileReader, PdfFileMerger
if not request.user.is_authenticated:
return render(request, "jobs/login.html", {"message": None})
equipment = Equipment.objects.filter(pk=equipment_id).first()
if not job:
raise Http404("test sheet error. Error code: get job failed")
pdf_write = PdfFileWriter()
user_properties=UserProperties.objects.get(user=request.user)
context = {
"equipment": equipment,
"job": equipment.equipments,
"test_sheet": equipment.sheet_eq,
"user_properties": user_properties,
"now": datetime.now().strftime("%b-%d-%Y %H:%M"),
"now_date": datetime.now().date()
}
html_sheet = render_to_string('jobs/test_sheet_gear1.html', context)
html_sheet2 = render_to_string('jobs/test_sheet_gear2.html', context)
pdf_content1 = pdfkit.from_string(html_sheet, None)
pdf_content2 = pdfkit.from_string(html_sheet2, None)
pdfadder = PdfFileMerger(strict=False)
pdfadder.append(pdf_content1)
pdfadder.append(pdf_content2)
pdf_adder.write("combined_sheets.pdf")
response = HttpResponse(pdf_adder, content_type="application/pdf")
response["Content-Disposition"] = f"filename={equipment.site_id}.pdf"
return response

I resolved this by hiring someone. The problem was that the objects being passed into the PyPDF2 function called PdfFileMerger() were not being recognized as pdf objects.
To resolve that, save the files (I place them in a folder called interim) using the second argument from the pdfkit.from_string() function, then assign the newly created files to independent variables using open() function, and finally proceed with the merging function by merging those variables.
def multi_test_sheet(request, equipment_id):
if not request.user.is_authenticated:
return render(request, "jobs/login.html", {"message": None})
from io import BytesIO
from PyPDF2 import PdfFileReader, PdfFileMerger
if not request.user.is_authenticated:
return render(request, "jobs/login.html", {"message": None})
equipment = Equipment.objects.filter(pk=equipment_id).first()
if not job:
raise Http404("test sheet error. Error code: get job failed")
page_quantity = 2 #temporary value for a property that will be added to either equipment or test sheet model
pdf_file_object = BytesIO()
stream = BytesIO()
pdf_write = PdfFileWriter()
user_properties=UserProperties.objects.get(user=request.user)
today = datetime.now()
now=today.strftime("%b-%d-%Y %H:%M")
now_date = today.date()
context = {
"equipment": equipment,
"job": equipment.equipments,
"test_sheet": equipment.sheet_eq,
"user_properties": user_properties,
"now": now,
"now_date": now_date
}
html_sheet = render_to_string('jobs/test_sheet_gear1.html', context)
html_sheet2 = render_to_string('jobs/test_sheet_gear2.html', context)
pdf_content1 = pdfkit.from_string(html_sheet, 'interm/test_sheet_gear1.pdf')
pdf_content2 = pdfkit.from_string(html_sheet2, 'interm/test_sheet_gear2.pdf')
pdfadder = PdfFileMerger(strict=False)
pdf1_v=PdfFileReader(open('interm/test_sheet_gear1.pdf', 'rb'))
pdf2_v=PdfFileReader(open('interm/test_sheet_gear2.pdf', 'rb'))
pdfadder.append(pdf1_v, import_bookmarks=False)
pdfadder.append(pdf2_v, import_bookmarks=False)
pdfadder.write('interm/'+str(user_properties.pk)+'combined_sheets.pdf')
output_file = open('interm/combined_sheets.pdf', 'rb')
response = HttpResponse(output_file, content_type="application/pdf")
response["Content-Disposition"] = f"filename={equipment.site_id}.pdf"
return response

create pdf and insert into Django data base i am using python 3.8 and Django 3.1.7 and xhtml2pdf==0.2.5

here is my code
def user_invoice_pdf(request,queryset):
template_path = 'user/order_details.html'
context = {'product':queryset}
response = HttpResponse(content_type='application/pdf')
response['Content-Disposition'] = 'attachment; filename="invoice.pdf"'
template = get_template(template_path)
html = template.render(context)
pdf = render_to_pdf(template_path,context)
if pdf:
receipt_file = File(BytesIO(pdf.response))
print(receipt_file,'receipt_file')
invoice = InvoiceData(user_info=request.userinvoie=receipt_file)
invoice.save()
else:
return response
return True

try this
file_name = first_name
file_name2 = file_name+'.'+ "pdf"
user_invoice_obj=Modelsname(user=request.user,order_product=queryset)
user_invoice_obj.save()
user_invoice_obj.invoice.save(file_name2, File(BytesIO(pdf)))

How to render_to_pdf with context of specific model object

I'm attempting to render a PDF and populate the template with specific data from the object that is being viewed.
I'm using xhtml12pdf / pisa. I've successfully rendered a generic (unpopulated) PDF, however when I add logic to populate a specific object's data, my context is being returned however the pdf is no longer being rendered.
views.py
class GeneratePdf(DetailView):
model = Request
template_name='request_response/response.html'
def get(self, request, *args, **kwargs):
context = super(GeneratePdf,self).get(request,*args,**kwargs)
return context
pdf = render_to_pdf('request_response/response.html',context)
if pdf:
response = HttpResponse(pdf,content_type='application/pdf')
filename = "PrivacyRequest_%s.pdf" %("1234")
content = "inline; filename='%s'" %(filename)
response['Content-Disposition'] = content
return response
return HttpResponse("Not Found")

Please show your render_to_pdf function. I assume that it like:
from io import BytesIO
from xhtml2pdf import pisa
from django.template.loader import get_template
def render_to_pdf(template, context):
template = get_template(template)
html = template.render(context)
result = BytesIO()
pdf = pisa.pisaDocument(BytesIO(html.encode("UTF-8")), result)
if not pdf.err:
return HttpResponse(result.getvalue(), content_type='application/pdf')
return None
You can remove context = super(GeneratePdf,self).get(request,*args,**kwargs) and return context.
As shown in the error message, context must be a dict. So change it to dictionary, like:
def get(self, request, *args, **kwargs):
context = {
'example1': 'This is example 1',
'some_foo': 'So many of foo function'
}
pdf = render_to_pdf('request_response/response.html',context)
if pdf:
response = HttpResponse(pdf,content_type='application/pdf')
filename = "PrivacyRequest_%s.pdf" %("1234")
content = "inline; filename='%s'" %(filename)
response['Content-Disposition'] = content
return response
return HttpResponse("Not Found")
FYI: This is another similiar question like yours and it has accepted answer.

Django return file as string, not as a file

I try to put statistics in excel spreadsheets in dynamic way, so when
excel.js
$('.js-excel').on('click', function () {
$.get(
'/ajax/stat_excel/',
{
'excel': 'loan',
'date_from': $('#date_from').val(),
'date_to': $('#date_to').val()
}
)
})
then
view.py
output = StringIO.StringIO()
workbook = xlsxwriter.Workbook(output)
if request.GET.get('excel') == 'loan':
workbook = loanChart.excel(workbook)
if request.GET.get('excel') == 'debet':
workbook = debetChart.excel(workbook)
workbook.close()
xlsx_data = output.getvalue()
response = HttpResponse(xlsx_data, mimetype='application/vnd.ms-excel')
response['Content-Type'] = 'application/vnd.ms-excel'
response['Content-Disposition'] = 'attachment; filename=report.xlsx'
return response
And I'm not sure what I'm doing wrong, because response be like
PK�������F��AS]$��w������xl/worksheets/sheet1.xml��[oɑ���W|W+#�>�dx(�{}�%j$�$
$������ʞ��8�]C�.��QU���������//�q�����ۛ:�����?|���77��y�n^<=�}�p�������������y����O���,���
Excel file generates excellent. I can see it, if I don't use StringIO
I'm not sure, what I need to use, Mimetype or Content-Type. Can't see any difference. Works exactly the same, no matter which type I write in response.
Where can be my problem?

Found answer here https://stackoverflow.com/a/4518775/4498908.
I can't use ajax for file download. But I can:
function download(path,val) {
window.location.href = path+"download.php?val="+val;
};