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Download modified CSV file in Flask [duplicate]

This question already has answers here:
Create and download a CSV file from a Flask view
(3 answers)
Closed 2 years ago.
My goal is to run my data de-identifying script and download my de-identified data from Flask. Right now, I have created a page to upload my file onto my web and I want to execute my de-identifying script using the execute button on my HTML and download the file.
My HTML:
{% block title %}Upload{% endblock %}
{% block main %}
<div class="container">
<div class="row">
<div class="col">
<h1>Upload the file</h1>
<hr>
<form action="/upload-file" method="POST" enctype="multipart/form-data">
<div class="form-group">
<label>Select file</label>
<div class="custom-file">
<input type="file" class="custom-file-input" name="Dataset" id="Dataset">
<label class="custom-file-label" for="Dataset">Select file...</label>
</div>
</div>
<button type="submit" class="btn btn-primary">De-indentify</button>
</form>
<form action="/upload-file" method="GET" enctype="multipart/form-data">
<button type="submit" class="btn btn-primary">Execute</button>
</form>
</div>
</div>
</div>
{% endblock %}
My App Flask route:
app.config["FILE_UPLOADS"] = "app/app/static/csv/uploads"
app.config["ALLOWED_FILE_EXTENSIONS"] = ["csv"]
def allowed_file(filename):
# We only want files with a . in the filename
if not "." in filename:
return False
# Split the extension from the filename
ext = filename.rsplit(".", 1)[1]
# Check if the extension is in ALLOWED_IMAGE_EXTENSIONS
if ext.upper() in app.config["ALLOWED_FILE_EXTENSIONS"]:
return True
else:
return False
#app.route("/upload-file", methods=["GET", "POST"])
def upload_file():
if request.method == "POST":
if request.files:
Dataset = request.files["Dataset"]
if Dataset.filename == "":
print("File must have a filename ")
return redirect(request.url)
if allowed_file(Dataset.filename):
print("That file extension is not allowed")
return redirect(request.url)
else:
filename = secure_filename(Dataset.filename)
Dataset.save(os.path.join(
app.config["FILE_UPLOADS"], filename))
print("Dataset saved")
return redirect(request.url)
return render_template("public/upload_file.html")
The file that I have uploaded:
Housing,Houseprice,Name,Neighbourhood,State
123556,100000,John,Bloomingdale,Washington
111777,250000,Ian,Bloomingdale,Washington
998273,250000,Tom,Spring Valley,California
My de-identifying script:
import pandas as pd
import uuid as u
# generate a pseudo-identifier sequesnce using python random number generator library uudi.
def uudi_generator(length):
uudi_list= list()
i=0
while i < length:
uudi_list.append(u.uuid4())
i+=1
return uudi_list
#import dataset
dataset = pd.read_csv('C:\\mylocation\\housing.csv', index_col=False)
# pseudo identifier
sLength = len(dataset['Housing'])
dataset.insert(0, 'uuid', pd.Series(uudi_generator(sLength), index=dataset.index))
#delete identifiabLe record from dataset
del dataset['Name']
del dataset['Neigbourhood']

Try this:
from flask import Response
csv_text = ""
for row in dataset.values:
csv_text += f"{row[0]},{row[1]},{row[2]},{row[3]}\n"
return Response(csv_text, mimetype='text/csv')
You don't even need to del the unwanted columns. Just don't add them in csv_text. You don't really even need pandas. You could read the csv as a text file, split('\n') and add the uuids when you compile the csv_text

Flask Application Showing 404 on Post

This is my first attempt at deploying a machine learning application and also my first time using flask. Essentially the user will fill out a form on an html page and the input from the form will be used as input to the machine learning model which is saved in a pickle file, model.pkl in the code below. I am running into one snag that I can't seem to break past..
Every time I submit from index.html and post to result.html I'm receiving a 404 error.
script.py:
#importing libraries
import os
import numpy as np
import flask
import pickle
from flask import Flask, render_template, request
app=Flask(__name__)
#app.route('/')
#app.route('/index')
def index():
return flask.render_template('index.html')
def ValuePredictor(to_predict_list):
to_predict = np.array(to_predict_list).reshape(1,12)
loaded_model = pickle.load(open("model.pkl","rb"))
result = loaded_model.predict(to_predict)
return result[0]
#app.route('/result',methods = ['POST'])
def result():
if request.method == 'POST':
to_predict_list = request.form.to_dict()
to_predict_list=list(to_predict_list.values())
to_predict_list = list(map(int, to_predict_list))
result = ValuePredictor(to_predict_list)
if int(result)==1:
prediction='Income more than 50K'
else:
prediction='Income less that 50K'
return render_template("result.html",prediction=prediction)
index.html:
<html>
<body>
<h3>Income Prediction Form</h3>
<div>
<form action="/result.html" method="POST">
<label for="age">Age</label>
<input type="text" id="age" name="age">
<br>
<label for="edu">Education</label>
<select id="edu" name="edu">
<option value="0">High School</option>
<option value="1">College Degree</option>
</select>
<br>
<label for="martial_stat">Marital Status</label>
<select id="martial_stat" name="martial_stat">
<option value="0">not married</option>
<option value="1">married</option>
</select>
<br>
<label for="gender">Gender</label>
<select id="gender" name="gender">
<option value="0">Female</option>
<option value="1">Male</option>
</select>
<br>
<input type="submit" value="Submit">
</form>
</div>
</body>
</html>
result.html:
<html>
<body>
<h1> {{ prediction }}</h1>
</body>
</html>
I can't seem to figure this out. My code never seems to reach the first line in the result() function. As soon as I submit from index.html http://127.0.0.1:5000/result.html throws a 404 error. Any suggestions?

The error is very simple here, the action property in index.html should just be
<form action="/result" method="POST">
instead of
<form action="/result.html" method="POST">
You want to use /result to go through your flask function. Hope this helps!

You are posting to the endpoint /result.html:
<form action="/result.html" method="POST">
... but your route in flask is defined as /result (with no .html):
#app.route('/result',methods = ['POST'])
def result():
...
These two need to match, so consider changing the route to result.html.

Instead of <form action="/result.html" method="POST">
Can Use <form action="{{ url_for('result') }}" method="POST">

Opening csv file in Python using Flask

So, I am trying to open an .csv file in Python using Flask. I copies the code from the Python library, but I go from one error message to the other and I don't know what I am doing wrong. The latest error code I get on the below code is: TypeError: invalid file:
Any ideas what I am doing wrong?
My Python code/Flash route is as follows:
#app.route("/admin", methods=["GET", "POST"])
#login_required
def admin():
"""Configure Admin Screen"""
# if user reached route via POST (as by submitting a form via POST)
if request.method == "POST":
# load csv file with portfolio data
with open(request.files["portfolios"]) as csvfile:
portfolios = csv.DictReader(csvfile)
# load csv file in dictionary
for row in portfolios:
print(row['first_name'], row['last_name'])
else:
return render_template("admin.html")
My html/Flask code is:
{% extends "layout.html" %}
{% block title %}
Admin
{% endblock %}
{% block main %}
<h2>Admin Console</h2>
<h3> Upload Portfolio Data</h2>
<form action="{{ url_for('admin') }}" method="post" enctype=multipart/form-data>
<fieldset>
<label class="control-label">Select Portfolio Upload File</label>
<input id="input-1" type="file" class="file" name="portfolios">
<h3>Upload Security Lists</h2>
<label class="control-label">Select Security Upload File</label>
<input id="input-1" type="file" class="file" name="securities">
<div class="form-group">
<button class="btn btn-default" type="submit" value = "upload">Upload</button>
</div>
</fieldset>
</form>
{% endblock %}

The file is already open. open takes a string filename and created an open file object, but you don't need to do that because objects in request.files are already open file-like objects.
portfolios = csv.DictReader(request.files['portfolios'])

Python Flask Sqlite3 Web App Delete from database table row

I have a very simple application that creates, removes, and updates records in a sqlite3 database using Python and Flask. I am currently working on the remove function and have hit a road block. Below is my code for my view that shows the records in the table:
<!doctype html>
<html>
<body>
<table border = 1>
<thead>
<td>Name</td>
<td>Address>/td<
<td>city</td>
<td>Pincode</td>
</thead>
{% for row in rows %}
<tr>
<td>{{row["name"]}}</td>
<td>{{row["addr"]}}</td>
<td> {{ row["city"]}}</td>
<td>{{row['pin']}}</td>
<td><form action = "/foo" method = "POST">
<button id ="w3-btn">delete</button>
</form> </td>
</tr>
{% endfor %}
</table>
Go back to home page
</body>
</html>
As can be seen from the code, I have a delete button for each record displayed. How can I make it such that if the user clicks on the delete button on any given row, that row will be deleted from the table? I would like to know how I can specify the selected row, and how I can send that information/data to 'foo' in my app.py, and how the function in app.py would take that data as an input argument.

If you have row["pin"]
then you can use hidden field in form with method="POST"
<form action="/foo" method="POST">
<input type="hidden" value="{{ row["pin"] }}"/>
<button id="w3-btn">delete</button>
</form>
or using method="GET" and ?id=some_id in url
<form action="/foo?id={{ row["pin"] }}" method="GET">
<button id="w3-btn">delete</button>
</form>
Or even as normal link (which you can style as button using CSS)
delete
In view you will have
# POST
#app.route('/foo', methods=['POST'])
def foo():
pin = requests.form.get('id')
print(pin)
# GET or normal link
#app.route('/foo')
def foo():
pin = requests.args.get('id')
print(pin)
Read doc: http://flask.pocoo.org/docs/0.11/
If you use url without ?id= but "/foo/some_id"
action="/foo/{{ row["pin"] }}"
delete
or using url_for()
action="{{ url_for('foo', pin=row["pin"]) }}"
TEST
then you will need
#app.route('/foo/<pin>')
def foo(pin):
print(pin)

Create a delete view that takes an id to delete.
#app.route('/<int:id>/delete', methods=['POST'])
def delete(id):
r = Record.query.get_or_404(id)
db.session.delete(r)
db.session.commit()
return redirect(url_for('index'))
The delete form's action is the generated url to the delete view.
<form method=post action="{{ url_for('delete', id=r.id) }}">
This assumes that each row has an id attribute. For example:
from flask import Flask, redirect, url_for, render_template_string
from flask_sqlalchemy import SQLAlchemy
app = Flask(__name__)
db = SQLAlchemy(app)
class Item(db.Model):
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String)
db.create_all()
db.session.add_all((
Item(name='abc'),
Item(name='def'),
Item(name='ghi'),
))
db.session.commit()
#app.route('/')
def index():
items = Item.query.all()
return render_template_string('''<ul>{% for item in items %}
<li>{{ item.name }} -
<form method=post action="{{ url_for('delete', id=item.id) }}">
<button type=submit>delete</button>
</form></li>
{% endfor %}</ul>''', items=items)
#app.route('/<int:id>/delete')
def delete(id):
item = Item.query.get_or_404(id)
db.session.delete(id)
db.session.commit()
return redirect(url_for('index'))
if __name__ == '__main__':
app.run(debug=True)

Simple dynamic forms with Flask/Flask-WTF

I need to build a simple form with a number of checkboxes. The problem is that I need the checkboxes to come from a csv file which would look like this:
data_so.csv
Name
A. Blabla
U. Blublu
I. Blibli
O. Bloblo
The form, right now, with some hard coded checkboxes, looks like this:
Instead of "Mr. 1", I'd need to have "A. Blabla", instead of "Ms. 2", I'd want "U. Blublu", etc. and instead of 3 checkboxes, I'd need 4, the number of entries in my csv file.
Here are my Flask files:
route_so.py
from flask import Flask, render_template, request, flash
from forms_so import ContactForm
import csv
app = Flask(__name__)
app.secret_key = 'development key'
#app.route('/', methods=['GET', 'POST'])
def home():
form = ContactForm()
if request.method == 'POST':
if form.validate() == False:
flash('All fields are required.')
return render_template('home_so.html', form=form)
else:
print(form.node_1.data,form.node_2.data,form.node_3.data)
return render_template('home_so.html', success=True)
elif request.method == 'GET':
return render_template('home_so.html', form=form)
if __name__ == '__main__':
app.run(debug=True)
form_so.py
from flask.ext.wtf import Form
import csv
from wtforms import TextField, RadioField, TextAreaField, SubmitField, validators, BooleanField
class ContactForm(Form):
# my attempt to force the creation of dynamic global variables
with open('/data_so.csv', 'rb') as f:
reader = csv.reader(f)
r = list(reader)
nodes = {}
for i in range(1,len(r)):
globals()[''.join("node_"+str(i))] = BooleanField(r[i][0])
# end of my attempt to force the creation of dynamic global variables
node_1 = BooleanField("Mr. 1")
node_2 = BooleanField("Ms. 2")
node_3 = BooleanField("Dr. 3")
# this needs to be dynamically set instead
submit = SubmitField("Send")
So I tried and created dynamic variables (in a dirty, hacky way). The problem now is that I don't know how to make the home_so.html work with an undifined number of variables...
home_so.html
{% extends "layout_so.html" %}
{% block content %}
{% if success %}
<p>Thank you for filling up our survey. We'll get back to you shortly.</p>
{% else %}
<form action="{{ url_for('home') }}" method=post>
{{ form.hidden_tag() }}
<h2>List of check boxes dynamically built from local csv file</h2>
#this needs to be dynamically set
{{ form.node_1.label }}
{{ form.node_1 }}
{{ form.node_2.label }}
{{ form.node_2 }}
{{ form.node_3.label }}
{{ form.node_3 }}
{{ form.submit }}
</form>
{% endif %}
{% endblock %}
Is there a way to accomplish this sort of things with a simple csv file? If not, what's the usual way to go about dynamically producing a form as it loads client-side?

{% for node in node_list_from_app %}
<p class="field"><label><input type="checkbox" name="node" value="{{ node }}"> {{ node }}</label></p>
{% endfor %}