Антон Бирюков

import os

from flask import Flask, render_template, flash, redirect, url_for, session, request, logging
from flask_sqlalchemy import SQLAlchemy
import urllib.request
from wtforms import Form, StringField, TextAreaField, PasswordField, validators
from passlib.hash import sha256_crypt
from functools import wraps
import json
from selenium import webdriver
from selenium.webdriver.common.keys import Keys

app = Flask(__name__)

app.config['SQLALCHEMY_DATABASE_URI'] = 'postgresql://webadmin:OELdtt45148@136.144.31.16/postgres'
app.secret_key = os.urandom(24)
db = SQLAlchemy(app)

class Klient (db.Model):
    id = db.Column(db.Integer, primary_key=True)
    inn = db.Column(db.String(50))
    password = db.Column(db.String(50))


class Katalog (db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name_tovar = db.Column(db.String(150))
    kat = db.Column(db.String(150))
    artikul = db.Column(db.String(150))
    ostatok = (db.Integer)
    price = (db.Float(50, 2))
    img_links = (db.String(250))

    def __repr__(self):
        return format(self.price)


# User login
@app.route('/', methods=['GET', 'POST'])
def login():
    if request.method == 'POST':
        # Get Form Fields
        username = request.form['username']
        password_candidate = request.form['password']

        # Create cursor
        #cur = mysql.connection.cursor()
        result = Klient.query.filter_by(inn=username).first()

        # Get user by username
        #result = cur.execute("SELECT * FROM users WHERE username = %s", [username])

        if result:
            # Get stored hash
            #data = cur.fetchone()
            data = result.password
            password = data
            #print(password)
            #print('ii',password_candidate)
            #print('iiu', username)

            # Compare Passwords
            #if sha256_crypt.verify(password_candidate, password):
            if password_candidate == password:
                # Passed
                session['logged_in'] = True
                session['username'] = username

                flash('You are now logged in', 'success')
                return redirect(url_for('test1'))
            else:
                error = 'Invalid login'
                return render_template('index.html', error=error)
            # Close connection
            #cur.close()
        else:
            error = 'Username not found'
            return render_template('index.html', error=error)

    return render_template('index.html')

# Check if user logged in
def is_logged_in(f):
    @wraps(f)
    def wrap(*args, **kwargs):
        if 'logged_in' in session:
            return f(*args, **kwargs)
        else:
            flash('Unauthorized, Please login', 'danger')
            return redirect(url_for('login'))
    return wrap

# test login
@app.route('/test', methods=['GET', 'POST'])
@is_logged_in
def test1():
    b1 = session ['username']
    incomplete = Katalog.query.filter_by(kat='s').all()
    #b3 = request.get_data()
    return render_template('test.html', b1=b1, b2=incomplete)

# test login
@app.route('/test1', methods=['GET', 'POST'])

def test2():

    response1 = urllib.request.urlopen('/test')
    data = response1.json()
    print(data)
    return


# Logout
@app.route('/logout')
@is_logged_in
def logout():
    session.clear()
    flash('You are now logged out', 'success')
    return redirect(url_for('login'))

if __name__ == '__main__':

    app.run(debug='True')

Решение нашлось само по себе. В таблице в базе присвоил данным значение string , А в выводе в шаблоне в подставил float

<p>Цена: <span class="item_price">{{ Katalog.artikul|float}}</span> руб.</p>

И в принципе заработало