views.clean_data.dataprep_helpers

export_csv(data, parent)

Save the current table as a CSV file.

Steps

1. Warn and abort if data is empty.
2. Ask the user for a target file path via QFileDialog.
3. Write data using :func:pandas.DataFrame.to_csv.
4. Inform the user of success or show a critical message on failure.

Source code in src/views/clean_data/dataprep_helpers.py

def export_csv(data: List[List[str]], parent: QWidget) -> None:
    """
    Save the current table as a CSV file.

    Steps:
      1. Warn and abort if ``data`` is empty.
      2. Ask the user for a target file path via ``QFileDialog``.
      3. Write ``data`` using :func:`pandas.DataFrame.to_csv`.
      4. Inform the user of success or show a critical message on failure.
    """

    # Warn and abort if data is empty.
    if not data:
        QMessageBox.warning(parent, "Export CSV", "The table is empty. Nothing to export.")
        return

    # Ask the user for a target CSV file path.
    file_path, _ = QFileDialog.getSaveFileName(parent, "Save as CSV", "", "CSV Files (*.csv);;All Files (*)")
    if not file_path:
        return

    try:
        # Create DataFrame and write CSV without index or header.
        df = pd.DataFrame(data)
        df.to_csv(file_path, index=False, header=False, encoding="utf-8")

        # Inform the user of successful export.
        QMessageBox.information(parent, "Export CSV", f"Successfully exported to:\n{file_path}")
    except Exception as e:  # pragma: no cover - GUI feedback
        # Log the error and inform the user on failure.
        logger.error(f"Error while exporting CSV: {e}")
        QMessageBox.critical(parent, "Export CSV", f"Could not export file:\n{e}")

export_excel(data, parent)

Save the current table as an Excel file.

Steps

1. Warn and abort if data is empty.
2. Ask the user for a target .xlsx path via QFileDialog.
3. Write data using :func:pandas.DataFrame.to_excel.
4. Inform the user of success or show a critical message on failure.

Source code in src/views/clean_data/dataprep_helpers.py

def export_excel(data: List[List[str]], parent: QWidget) -> None:
    """
    Save the current table as an Excel file.

    Steps:
      1. Warn and abort if ``data`` is empty.
      2. Ask the user for a target ``.xlsx`` path via ``QFileDialog``.
      3. Write ``data`` using :func:`pandas.DataFrame.to_excel`.
      4. Inform the user of success or show a critical message on failure.
    """

    # Warn and abort if data is empty.
    if not data:
        QMessageBox.warning(parent, "Export Excel", "The table is empty. Nothing to export.")
        return

    # Ask the user for a target Excel file path.
    file_path, _ = QFileDialog.getSaveFileName(parent, "Save as Excel", "", "Excel Files (*.xlsx);;All Files (*)")
    if not file_path:
        return

    try:
        # Create DataFrame from data.
        df = pd.DataFrame(data)

        # Ensure file name ends with .xlsx.
        if not file_path.lower().endswith(".xlsx"):
            file_path += ".xlsx"

        # Write DataFrame to Excel.
        df.to_excel(file_path, index=False, header=False, engine="openpyxl")

        # Inform the user of successful export.
        QMessageBox.information(parent, "Export Excel", f"Successfully exported to:\n{file_path}")

        # Log the export action.
        logger.info(f"Table exported as Excel to {file_path}")
    except Exception as e:  # pragma: no cover - GUI feedback
        # Log the error and inform the user on failure.
        logger.error(f"Error while exporting Excel: {e}")
        QMessageBox.critical(parent, "Export Excel", f"Could not export file:\n{e}")

validate_first_row(table, parent)

Check the first row for missing or invalid values.

Steps

1. Gather all values of the first row and detect empty or NaN strings.
2. If none found, return "ignore".
3. Otherwise, show a dialog offering three choices: a. Proceed anyway. b. Stay and let the user fix manually. c. Autofill missing names with col_<index>.
4. Return a string describing the chosen action.

Source code in src/views/clean_data/dataprep_helpers.py

def validate_first_row(table: QTableWidget, parent: QWidget) -> str:
    """
    Check the first row for missing or invalid values.

    Steps:
      1. Gather all values of the first row and detect empty or ``NaN`` strings.
      2. If none found, return ``"ignore"``.
      3. Otherwise, show a dialog offering three choices:
         a. Proceed anyway.
         b. Stay and let the user fix manually.
         c. Autofill missing names with ``col_<index>``.
      4. Return a string describing the chosen action.
    """

    # Return "ignore" if there are no rows to validate.
    row_count = table.rowCount()
    if row_count == 0:
        logger.debug("No rows to validate.")
        return "ignore"

    # Collect values from the first row.
    first_row_values: List[str] = []
    for c in range(table.columnCount()):
        item = table.item(0, c)
        first_row_values.append(item.text() if item else "")

    # Identify indices of empty or NaN cells.
    bad_indices: List[int] = []
    for c, val in enumerate(first_row_values):
        v = val.strip()
        if v == "" or v.lower() == "nan":
            bad_indices.append(c)

    # Return "ignore" if no invalid cells found.
    if not bad_indices:
        logger.debug("First row validation passed.")
        return "ignore"

    # Warn about invalid cells and ask user for action.
    logger.warning(f"Found {len(bad_indices)} invalid cells in first row.")
    msg = QMessageBox(parent)
    msg.setWindowTitle("Missing or Invalid Column Names")
    msg.setText("Some cells in the first row are empty or contain NaN. What would you like to do?")

    # Provide action buttons: ignore, stay, autofill.
    btn_ignore = msg.addButton("Proceed anyway", QMessageBox.AcceptRole)  # type: ignore[arg-type]
    btn_stay = msg.addButton("Stay and fix manually", QMessageBox.RejectRole)  # type: ignore[arg-type]
    btn_autofill = msg.addButton("Auto-fill missing names", QMessageBox.DestructiveRole)  # type: ignore[arg-type]
    msg.setDefaultButton(btn_stay)
    msg.exec()

    # Handle user choice accordingly.
    clicked = msg.clickedButton()
    if clicked is btn_ignore:
        # User chose to proceed anyway.
        logger.info("User chose to proceed anyway.")
        return "ignore"
    elif clicked is btn_autofill:
        # Autofill invalid cells with placeholder names.
        logger.info(f"Auto-filling {len(bad_indices)} invalid cells.")
        for c in bad_indices:
            table.setItem(0, c, QTableWidgetItem(f"col_{c}"))
        table.resizeColumnsToContents()
        return "autofill"
    else:
        # User chose to stay and fix manually.
        return "stay"