pset7 finance python Login question

Question

Hello all a problem I have run into is that I cannot login in registered users it just returns me the invalid username/password page when I try to login. Does anyone know what the problem in my code is?

  from cs50 import SQL
from flask import Flask, flash, redirect, render_template, request, session, url_for
from flask_session import Session
from passlib.apps import custom_app_context as pwd_context
from tempfile import mkdtemp

from helpers import *

# configure application
app = Flask(__name__)

# ensure responses aren't cached
if app.config["DEBUG"]:
    @app.after_request
    def after_request(response):
        response.headers["Cache-Control"] = "no-cache, no-store, must-revalidate"
        response.headers["Expires"] = 0
        response.headers["Pragma"] = "no-cache"
        return response

# custom filter
app.jinja_env.filters["usd"] = usd

# configure session to use filesystem (instead of signed cookies)
app.config["SESSION_FILE_DIR"] = mkdtemp()
app.config["SESSION_PERMANENT"] = False
app.config["SESSION_TYPE"] = "filesystem"
Session(app)

# configure CS50 Library to use SQLite database
db = SQL("sqlite:///finance.db")

@app.route("/")
@login_required
def index():
    return apology("TODO")

@app.route("/buy", methods=["GET", "POST"])
@login_required
def buy():
    """Buy shares of stock."""
    return apology("TODO")

@app.route("/history")
@login_required
def history():
    """Show history of transactions."""
    return apology("TODO")

@app.route("/login", methods=["GET", "POST"])
def login():
    """Log user in."""

    # forget any user_id
    session.clear()

    # if user reached route via POST (as by submitting a form via POST)
    if request.method == "POST":

        # ensure username was submitted
        if not request.form.get("username"):
            return apology("must provide username")

        # ensure password was submitted
        elif not request.form.get("password"):
            return apology("must provide password")

        # query database for username
        rows = db.execute("SELECT * FROM users WHERE username = :username", username=request.form.get("username"))

        # ensure username exists and password is correct
        if len(rows) != 1 or not pwd_context.verify(request.form.get("password"), rows[0]["hash"]):
            return apology("invalid username and/or password")

        # remember which user has logged in
        session["user_id"] = rows[0]["id"]

        # redirect user to home page
        return redirect(url_for("index"))

    # else if user reached route via GET (as by clicking a link or via redirect)
    else:
        return render_template("login.html")

@app.route("/logout")
def logout():
    """Log user out."""

    # forget any user_id
    session.clear()

    # redirect user to login form
    return redirect(url_for("login"))

@app.route("/quote", methods=["GET", "POST"])
@login_required
def quote():
    """Get stock quote."""
    if request.method == "POST":
        if not request.form.get("symbol"):
            return apology("missing symbol")

        #look up stock symbol and print onto quoted template
        quote = lookup(request.form.get("symbol"))
        if quote == None:
            return apology("missing correct symbol")
        return render_template("quoted.html", stock=quote.get("name"), sym=quote.get("symbol"), mon=quote.get("price"))

    return render_template("quote.html")
    #return apology("TODO")

@app.route("/register", methods=["GET", "POST"])
def register():
    """Register user."""

    if request.method == "POST":
        #make sure fields are not empty in fields
        if not request.form.get("username"):
            return apology("missing username")
        elif not request.form.get("password"):
            return apology("missing password")
        if request.form.get("password") != request.form.get("passwordc"):
            return apology("Passwords do not match")

        hash = pwd_context.encrypt("password")
        #make sure username is in database
        result = db.execute("INSERT INTO users (username, hash) VALUES(:username, :hash)", username = request.form.get("username"), hash = hash)
        if not result:
            return apology("username already exists")

        #store result incrementing id into session
        session["user_id"] = result

        return redirect(url_for("index"))

    else:
        return render_template("register.html")

@app.route("/sell", methods=["GET", "POST"])
@login_required
def sell():
    """Sell shares of stock."""
    return apology("TODO")

Im not sure if it has to do with my sessions in register def.

Answer 1

1. I do not think, that the way how you get hash of the password is correct. Try to pass to the function a value, that the user entered, but not the string "password" hash = pwd_context.encrypt(request.form.get("password"))

2. Look how you store user_id in session. You need to add rows = db.execute("SELECT * FROM users WHERE username = :username", username = request.form.get("username")) session["user_id"] = rows[0]["id"] because the result does not store information about "id" .The right way to access field "id" in rows is rows[0]["id"]. It means something like "give me the first row in result (if everything is correct in result will be only 1 row) and retrieve the value of the key "id" " Try to create another file tmp.py and execute following code

from cs50 import SQL db = SQL("sqlite:///finance.db") rows = db.execute("SELECT * FROM users WHERE username = :username", username = "David") print (rows)