Python Docstrings

def parse_date(date_str):
    """Parse a date string into a datetime object.

    Args:
        date_str (str): Date string in ISO 8601 format (YYYY-MM-DD).

    Returns:
        datetime: Parsed datetime object.

    Raises:
        ValueError: If the string does not match ISO 8601 format.
    """

def compute_rmse(y_true, y_pred):
    """
    Compute root mean squared error.

    Parameters
    ----------
    y_true : array-like of shape (n_samples,)
        Ground truth target values.
    y_pred : array-like of shape (n_samples,)
        Estimated target values.

    Returns
    -------
    float
        RMSE value.
    """

def connect(host, port=5432):
    """
    Connect to a PostgreSQL database.

    :param host: Hostname or IP of the database server.
    :type host: str
    :param port: Port number. Defaults to 5432.
    :type port: int
    :returns: Active database connection.
    :rtype: psycopg2.extensions.connection
    :raises ConnectionError: If the server is unreachable.
    """