Checking Tuples in a list

Question

So i am working on a program that is and I am stuck. I have a login and signup system that saves new signups in a mysql database. At the start of the program I take the passwords and names and put them together in a tuple. Then i put that tuple in a list. If i wanna login it cant check a tuple in that list. Here is my code: Login:

def login():
    userKnown = input("Hallo, heeft u al een account? y/n ")

    if userKnown == "y":
        user = input("username: ")
        passw = input("password: ")
        userjoin = (user,passw)
        if userjoin in bigdata:
            print("login succesful")
        else:
            print("try again")
   

UploadData:

def uploadData():
    print("Bezig met uploaden.")
    mycursor.execute("SELECT name, password FROM userData")
    data = mycursor.fetchall()
    bigdata.append(data)
    print("Upload worked. \n")

I hope someone can help me.

A fix to the login system.

Answer 1

I solved it thanks to Georg Richter.

I used the Where function in select and that worked

Here is the code:

def login():
    userKnown = input("Hallo, heeft u al een account? y/n ")

    if userKnown == "y":
        user = input("username: ")
        passw = input("password: ")
        userB = (user, passw)
        query = 'SELECT name, password FROM userData WHERE name =%s'
        name = (user,)
        mycursor.execute(query, name)
        userA = mycursor.fetchone()
        print(userA)
        if userA == userB:
            print("succes")
        else:
            print("failed")

Answer 2

I think the error is that bigdata does not exist into your login function. Try this: def login(bigdata) and call the function in this way: login(bigdata)

Answer 3

Try using try block to find the user its easier this way.

try:
    pass
    #code to search database
except Exception as e:
    print(e)

SELECT has a WHERE clause where you can specify user and password to optimize your application.