Backend - I wrote a python script that creates a csv file after some aggregation.
Frontend - Once the method finished running and the .csv file is generated and saved to a directory in the server, I want to be able to prompt the user to save the .csv file on their local computer (just like the windows prompt you get when you press "save as..." on a webpage).
This is an example of what I've done so far from what I learned in Return Excel file in Flask app and Download a file when button is pressed on web application? :
Sample code:
with open(save_path + unique_filename + ".csv", 'w', encoding = 'utf8') as g:
writer = csv.writer(g, lineterminator = '\n')
writer.writerow(['name', 'place', 'location'])
HTML:
#app.route('/login', method='POST')
def do_login():
category = request.forms.get('category')
return '''
<html><body>
Hello. Save Results
</body></html>
'''
#app.route("/getCSV", methods = ['GET', 'POST'])
def getPlotCSV():
return send_from_directory(save_path + unique_filename + ".csv", as_attachment=True)
if __name__ == "__main__":
run(app, host = 'localhost', port = 8000)
My questions are:
1) send_from_directory is from flask, what is the bottle equivalent?
2) Where in the code do I place the csv I created so the user can download it to their local machine?
3) What else is wrong with my code?
Bottle example: From https://bottlepy.org/docs/dev/tutorial.html
#route('/download/<filename:path>')
def download(filename):
return static_file(filename, root='/path/to/static/files', download=filename)
Related
I have a dash app where I want the user to be able to download a pdf-report.
I am able to make it work locally with pdfkit and jinja based on this method, but to make it work I have to save the file on the server, then fetch it for download. My users might not want this, so I want to save the temporary file only in memory (client side).
This is my code:
from dash import Dash, dcc, html, Input, Output
import pdfkit
import jinja2
# Set up sample pdf with pdfkit and jinja based on this tutorial: https://www.youtube.com/watch?v=1IYtkkEOuoU
my_name = "Frank "
item1 = "TV"
today_date = "2022"
context = {'my_name': my_name,
'item1': item1,
'today_date': today_date}
template_loader = jinja2.FileSystemLoader('./')
template_env = jinja2.Environment(loader=template_loader)
html_template = 'my-basic-template.html'
template = template_env.get_template(html_template)
output = template.render(context)
# downloaded wkhtmltopdf locally:
path_wkhtmltopdf = r'C:\Program Files\wkhtmltopdf\bin\wkhtmltopdf.exe'
config = pdfkit.configuration(wkhtmltopdf=path_wkhtmltopdf)
output_pdf = 'pdf_generated.pdf'
pdfkit.from_string(output, output_pdf, configuration=config)
# Make Dash app
app = Dash(__name__)
app.layout = html.Div([
html.Button("Download pdf", id="btn-download-pdf"),
dcc.Download(id="download-pdf")
])
#app.callback(
Output("download-pdf", "data"),
Input("btn-download-pdf", "n_clicks"),
prevent_initial_call=True,
)
def func(n_clicks):
pdf = pdfkit.from_string(output, configuration=config)
print(output)
return dcc.send_file("pdf_generated.pdf", "test_pdf.pdf")
if __name__ == '__main__':
app.run_server(debug=True)
Is there a better way to do this?
I am completely lost and I do not know how to approach the following problem which my boss assigned to me.
I have to create an exe - file containing a code which works as follows when I run it: It sends a certain file, say file_A, to a server. When the server receives this file it sends back a json-file, say file_B, which contains an url. More precisely, the attribute of the json-file contains the url. The code should then open the url in a browser.
And here are the details:
The above code (one version in tcl) must accept three parameters and a fourth optional parameter (so, it is not necessary to pass a fourth parameter). The three parameters are: server, type and file.
server: this is the path to the server. For example, https://localhost:0008.
type: this is the type of the file (file_A) to be send to the server: xdt / png
file: this is the path to the file (file_A) to be send to the server.
The fourth optional parameter is:
wksName: if this paramater is given, then the url should be opened with it in the browser.
I got an example code for the above procedure written in python. It should serve as an orientation. I do not know anything about this language but to a large extend I understand the code. It looks as follows:
#!/usr/bin/env python
# -*- coding: utf-8 -*-
import platform
import sys
import webbrowser
import requests
args_dict = {}
for arg in sys.argv[1:]:
if '=' in arg:
sep = arg.find('=')
key, value = arg[:sep], arg[sep + 1:]
args_dict[key] = value
server = args_dict.get('server', 'http://localhost:0008')
request_url = server + '/NAME_List_number'
type = args_dict.get('type', 'xdt')
file = args_dict.get('file', 'xdtExamples/xdtExample.gdt')
wksName = args_dict.get('wksName', platform.node())
try:
with open(file, 'rb') as f:
try:
r = requests.post(request_url, data={'type': type}, files={'file': f})
request_url = r.json()['url'] + '?wksName=' + wksName
webbrowser.open(url = request_url, new = 2)
except Exception as e:
print('Error:', e)
print('Request url:', request_url)
except:
print('File \'' + file + '\' not found')
As you can see, the crucial part of the above code is this:
try:
with open(file, 'rb') as f:
try:
r = requests.post(request_url, data={'type': type}, files={'file': f})
request_url = r.json()['url'] + '?wksName=' + wksName
webbrowser.open(url = request_url, new = 2)
except Exception as e:
print('Error:', e)
print('Request url:', request_url)
except:
print('File \'' + file + '\' not found')
Everything else above it are just definitions. If possible, I would like to translate the above code into tcl. Could you please help me with this issue?
It doesn't have to be a 1-1 "tcl-translation" as long as it works as described above, and hopefully as simple as the above one.
I am not familiar with concepts such as sending/receiving data to/from servers, reading json-files etc.
Any help is welcome.
My google drive is linked to my google colab notebook. Using the pytorch library torch.load($PATH) fails to load this 219 Mo file (pre-trained neural network) (https://drive.google.com/drive/folders/1-9m4aVg8Hze0IsZRyxvm5gLybuRLJHv-) which is in my google drive. However it works fine when I do it locally on my computer. The error i get on google collab is: (settings: Python 3.6, pytorch 1.3.1):
state_dict = torch.load(model_path)['state_dict']
File "/usr/local/lib/python3.6/dist-packages/torch/serialization.py", line 303, in load
return _load(f, map_location, pickle_module)
File "/usr/local/lib/python3.6/dist-packages/torch/serialization.py", line 454, in _load
return legacy_load(f)
File "/usr/local/lib/python3.6/dist-packages/torch/serialization.py", line 380, in legacy_load
with closing(tarfile.open(fileobj=f, mode='r:', format=tarfile.PAX_FORMAT)) as tar,
File "/usr/lib/python3.6/tarfile.py", line 1589, in open
return func(name, filemode, fileobj, **kwargs)
File "/usr/lib/python3.6/tarfile.py", line 1619, in taropen
return cls(name, mode, fileobj, **kwargs)
File "/usr/lib/python3.6/tarfile.py", line 1482, in init
self.firstmember = self.next()
File "/usr/lib/python3.6/tarfile.py", line 2297, in next
tarinfo = self.tarinfo.fromtarfile(self)
File "/usr/lib/python3.6/tarfile.py", line 1092, in fromtarfile
buf = tarfile.fileobj.read(BLOCKSIZE)
OSError: [Errno 5] Input/output error```
Any help would be much appreciated!
Large sized files are automatically analyzed for virus on Drive, every time you attempt to download a large file you have to pass thru this scan, making it hard to reach the download link.
You could download the file directly using the Drive API and then pass it to the torch, it shouldn't be hard to implement on Python, I've made a sample on how to Download your file and pass it to Torch.
import torch
import pickle
import os.path
import io
from googleapiclient.discovery import build
from google_auth_oauthlib.flow import InstalledAppFlow
from google.auth.transport.requests import Request
from googleapiclient.http import MediaIoBaseDownload
from __future__ import print_function
url = "https://drive.google.com/file/d/1RwpuwNPt_r0M5mQGEw18w-bCfKVwnZrs/view?usp=sharing"
# If modifying these scopes, delete the file token.pickle.
SCOPES = (
'https://www.googleapis.com/auth/drive',
)
def main():
"""Shows basic usage of the Sheets API.
Prints values from a sample spreadsheet.
"""
creds = None
# The file token.pickle stores the user's access and refresh tokens, and is
# created automatically when the authorization flow completes for the first
# time.
if os.path.exists('token.pickle'):
with open('token.pickle', 'rb') as token:
creds = pickle.load(token)
# If there are no (valid) credentials available, let the user log in.
if not creds or not creds.valid:
if creds and creds.expired and creds.refresh_token:
creds.refresh(Request())
else:
flow = InstalledAppFlow.from_client_secrets_file(
'credentials.json', SCOPES)
creds = flow.run_local_server(port=0)
# Save the credentials for the next run
with open('token.pickle', 'wb') as token:
pickle.dump(creds, token)
drive_service = build('drive', 'v2', credentials=creds)
file_id = '1RwpuwNPt_r0M5mQGEw18w-bCfKVwnZrs'
request = drive_service.files().get_media(fileId=file_id)
# fh = io.BytesIO()
fh = open('file', 'wb')
downloader = MediaIoBaseDownload(fh, request)
done = False
while done is False:
status, done = downloader.next_chunk()
print("Download %d%%." % int(status.progress() * 100))
fh.close()
torch.load('file')
if __name__ == '__main__':
main()
To run it you'll have first to:
Enable the Drive API for your account
Install the Google Drive API libraries,
This takes no more than 3 minutes and is properly explained on the Quickstart Guide for Google Drive API, just follow steps 1 and 2 and run the provided sample code from above.
It worked by uploading directly the file to google colab instead of loading it from google drive using:
from google.colab import files
uploaded= files.upload()
I guess this solution is similar to the one proposed by #Yuri
I have the following flask app where I want to be able to upload a TXT or TSV file to a form. The problem is, when I try to upload a TXT file, it works, but when I try to upload a TSV file, I get the following error:
File "/Users/cdastmalchi/Desktop/author_script/main.py", line 89, in process_file
if not places_exist(os.path.join(app.config['UPLOAD_FOLDER'], filename)):
File "/Users/cdastmalchi/Desktop/author_script/main.py", line 27, in places_exist
infile = open(filename, 'rU')
IOError: [Errno 2] No such file or directory: './Authors_Template.tsv'
Authors_Template.tsv is a template file that gets downloaded from the form and goes into the Downloads, and then I want users to be able to edit this template and then re-upload it. When I make the template Authors_Template.txt instead and then Download and re-upload it, it works. How can I solve this problem? I've even tried narrowing down the ALLOWED_EXTENSIONS list to just TSV and I still get the same issue.
app.py
from werkzeug.utils import secure_filename
import flask, string, random
import json
import subprocess
import os
import re
import time
UPLOAD_FOLDER = '.'
ALLOWED_EXTENSIONS = set(['txt','tsv'])
app = flask.Flask(__name__)
app.config['UPLOAD_FOLDER'] = UPLOAD_FOLDER
app.secret_key = ''.join(random.choice(string.ascii_letters) for _ in range(20)) #needed to use flask.session
def allowed_file(filename):
return '.' in filename and \
filename.rsplit('.', 1)[1] in ALLOWED_EXTENSIONS
def places_exist(filename):
infile = open(filename, 'rU')
placeDict = {}
addresses_temp = []
addresses = []
places_temp =[]
places = []
places_exist = True
for i in infile:
item = i.rstrip("\n").split("\t")
places_temp.append(item[0])
addresses_temp.append(item[1])
p_index = (places_temp.index('Place')) + 1
a_index = (addresses_temp.index('Address')) + 1
places = places_temp[p_index:]
addresses = addresses_temp[a_index:]
infile.close()
infile = open(filename, 'rU')
return places_exist
#app.route('/', methods=['GET'])
def home():
return flask.render_template('index.html')
#app.route('/process_file', methods=['POST'])
def process_file():
#here, you can run all the checks as before, but instead of flash, you can return jsonified results to read in the front-end
if 'file' not in flask.request.files or not flask.request.files['file'].filename:
return flask.jsonify({'result':'False', 'message':'no files selected'})
return flask.redirect(url_for('home'))
file = flask.request.files['file']
filename = secure_filename(file.filename)
if not allowed_file(file.filename):
return flask.jsonify({'result':'False', 'message':'Must be TXT file!'})
return flask.redirect(url_for('home'))
if not places_exist(os.path.join(app.config['UPLOAD_FOLDER'], filename)):
return flask.jsonify({'result':'False', 'message':'There is an affiliation missing from your Place list. Please re-try.'})
return flask.redirect(url_for('home'))
file.save(os.path.join(app.config['UPLOAD_FOLDER'], filename))
flask.session['filename'] = filename
return flask.jsonify({'result':'True'})
UPDATE:
def process_file():
#here, you can run all the checks as before, but instead of flash, you can return jsonified results to read in the front-end
if 'file' not in flask.request.files or not flask.request.files['file'].filename:
return flask.jsonify({'result':'False', 'message':'no files selected'})
return flask.redirect(url_for('home'))
file = flask.request.files['file']
filename = secure_filename(file.filename)
if not allowed_file(file.filename):
return flask.jsonify({'result':'False', 'message':'Must be TXT file!'})
return flask.redirect(url_for('home'))
# Save the file in the temp folder
file.save(os.path.join(app.config['TEMP_FOLDER'], filename))
# Process the file
if not places_exist(os.path.join(app.config['TEMP_FOLDER'], filename)):
return flask.jsonify({'result':'False', 'message':'There is an affiliation missing from your Place list. Please re-try.'})
return flask.redirect(url_for('home'))
file.save(os.path.join(app.config['UPLOAD_FOLDER'], filename))
flask.session['filename'] = filename
return flask.jsonify({'result':'True'})
You are trying to read a file before its writing in your directory. First you need to save the file in your application upload directory then read it.
def process_file():
# here, you can run all the checks as before, but instead of flash, you can return jsonified results to read in the front-end
if 'file' not in flask.request.files or not flask.request.files['file'].filename:
return flask.jsonify({'result':'False', 'message':'no files selected'})
return flask.redirect(url_for('home'))
file = flask.request.files['file']
filename = secure_filename(file.filename)
if not allowed_file(file.filename):
return flask.jsonify({'result':'False', 'message':'Must be TXT file!'})
return flask.redirect(url_for('home'))
# Save the file in the correct Location
file.save(os.path.join(app.config['UPLOAD_FOLDER'], filename))
# Process your file already saved
if not places_exist(os.path.join(app.config['UPLOAD_FOLDER'], filename)):
return flask.jsonify({'result':'False', 'message':'There is an affiliation missing from your Place list. Please re-try.'})
return flask.redirect(url_for('home'))
flask.session['filename'] = filename
return flask.jsonify({'result':'True'})
EDIT: You have to be careful if you need to check the file before saving, if you save right away you will override your old file, a good approach will be to save the file in a temp location, check that file and then save in the final directory, and obviously delete the file in the tmp folder.
PS: Also you have 2 return, if you need to respond as a HTML or JSON you have to check the headers of the request.
I have a page that displays a list of files in a directory. When the user clicks on the Download button, all of these files are zipped into a single file, which is then offered for download. I know how to send this file to the browser when the button is clicked, and I know how to reload the current page (or redirect to a different one), but is it possible to do both in the same step? Or would it make more sense to redirect to a different page with a download link?
My download is initiated with the Flask API's send_from_directory. Relevant test code:
#app.route('/download', methods=['GET','POST'])
def download():
error=None
# ...
if request.method == 'POST':
if download_list == None or len(download_list) < 1:
error = 'No files to download'
else:
timestamp = dt.now().strftime('%Y%m%d:%H%M%S')
zfname = 'reports-' + str(timestamp) + '.zip'
zf = zipfile.ZipFile(downloaddir + zfname, 'a')
for f in download_list:
zf.write(downloaddir + f, f)
zf.close()
# TODO: remove zipped files, move zip to archive
return send_from_directory(downloaddir, zfname, as_attachment=True)
return render_template('download.html', error=error, download_list=download_list)
Update: As a workaround, I am now loading a new page with the button click, which lets the user initiate the download (using send_from_directory) before returning to the updated listing.
Are you running the flask app behind a front end web server such as nginx or apache (which would be the best way to handle the downloading of files). If you're using nginx you can use the 'X-Accel-Redirect' header. For this example I'll use the directory /srv/static/reports as the directory you're creating the zipfiles in and wanting to serve them out of.
nginx.conf
in the server section
server {
# add this to your current server config
location /reports/ {
internal;
root /srv/static;
}
}
your flask method
send the header to nginx to server
from flask import make_response
#app.route('/download', methods=['GET','POST'])
def download():
error=None
# ..
if request.method == 'POST':
if download_list == None or len(download_list) < 1:
error = 'No files to download'
return render_template('download.html', error=error, download_list=download_list)
else:
timestamp = dt.now().strftime('%Y%m%d:%H%M%S')
zfname = 'reports-' + str(timestamp) + '.zip'
zf = zipfile.ZipFile(downloaddir + zfname, 'a')
for f in download_list:
zf.write(downloaddir + f, f)
zf.close()
# TODO: remove zipped files, move zip to archive
# tell nginx to server the file and where to find it
response = make_response()
response.headers['Cache-Control'] = 'no-cache'
response.headers['Content-Type'] = 'application/zip'
response.headers['X-Accel-Redirect'] = '/reports/' + zf.filename
return response
If you're using apache, you can use their sendfile directive http://httpd.apache.org/docs/2.0/mod/core.html#enablesendfile