Wert App frequently asked questions and troubleshooting

The app crashes on startup — what should I check?

The most common causes of a crash on startup are:

passwordBDD.txt is missing or in the wrong location. The file must exist in the project root (the same directory as main.py). If it is missing, conexion.py will raise a FileNotFoundError before the app window opens.
The password in passwordBDD.txt is incorrect. If the password doesn’t match the MySQL root password, the connection will be refused.
MySQL is not running. The app connects to MySQL at startup via setTables(). Make sure your MySQL service is active before launching the app.
The registro_usuarios database does not exist. The app creates its tables automatically, but it does not create the database. You must create it manually first. See the next question for the SQL command.

How do I create the MySQL database?

The app does not create the database automatically. Before running main.py for the first time, connect to your MySQL instance and run:

CREATE DATABASE registro_usuarios;

Once the database exists, the app will create the usuarios and notas tables on its own the first time it starts.

Why does login fail even with the correct credentials?

A few things to check:

Passwords are stored as plain text. There is no hashing. The value stored at registration is compared directly against what you enter at login.
Leading and trailing whitespace is stripped. Both the username and password fields call .strip() before being sent to the database, so accidental spaces won’t cause a mismatch.
The user account may not exist. Use a MySQL client to verify the user exists in the usuarios table, or try registering again if registration previously failed silently.

Can I change the MySQL host, user, or port?

Not through a configuration file — these values are hardcoded in database/conexion.py. To use a different host, user, or port, open that file and edit the parameters in the getConexion function directly:

conexion = mysql.connector.connect(
    user='root',
    password=password,
    host='localhost',
    database='registro_usuarios',
    port=3306
)

Replace the values as needed and restart the app.

Why are currency rates sometimes unavailable?

The currency conversion feature depends on the ExchangeRate API. Rates may be unavailable for two reasons:

The API is rate-limited. The free tier has a monthly request limit. Once exceeded, requests return a non-200 response.
The API key has expired or been revoked. The key is hardcoded in api/change_api.py. If it stops working, it must be replaced in that file.

When a request fails for any reason, get_rate returns None and the conversion result will not be displayed.

What does 'Dato no disponible' mean in economic data?

This message appears when the World Bank API returns null for a specific country, indicator, and year combination. Not all indicators have data for every country and year.The format_eco_data method in api/world_bank_api.py handles this case explicitly:

elif valor == None:
    texto += f'{año}: Dato no disponible \n'

It is not an error — it simply means the World Bank has not published data for that data point.

Can two users have notes with the same title?

Different users can use the same note title. The notas table enforces a UNIQUE constraint on the combination of id (the user’s ID) and titulo (the note title):

UNIQUE (id, titulo)

This means a single user cannot have two notes with the same title, but two different users can each have a note titled the same thing without conflict.

What is the minimum password length?

6 characters. This is enforced in modules/logica_register.py before the registration request is sent to the database:

if tamanio_clave < 6:
    QMessageBox.critical(self, 'Error', 'La contraseña debe tener al menos 6 caracteres')
    return

There is no maximum length enforced in the application, though the password column is defined as VARCHAR(255).

How are the 5 most recent data points selected for economic indicators?

The WorldBankAPI.get_eco_info method passes per_page=5 as a query parameter when calling the World Bank API:

params = {'format': 'json', 'per_page': 5}

The World Bank API returns results in reverse chronological order by default, so the 5 most recent available years are returned first.

Is the app available for Windows, macOS, and Linux?

Yes. Wert App is built with PyQt5, which is a cross-platform GUI framework. It runs on Windows, macOS, and Linux without code changes.To run the app on any platform, you need:

Python 3
MySQL Server running locally
The Python dependencies installed (PyQt5, mysql-connector-python, requests)

Start the app with:

python main.py

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