def get_unique_df_values(df, dtypes):
    """
    # Returns a dictionary of type {dict: list}, corresponding to {columns -> unique values}

    # Parameters:
    #    df (Pandas dataframe): The dataframe from which extract the columns unique values
    #   dtypes (dictionary): Dictionary of column types

    # Returns:
    #    A dictionary of {columns -> unique values}

    """

    unique_values = {}

    for i, col in enumerate(df.columns): # Not numeric column

        if (dtypes[col] == 'object'): # If categorical column

            # Unique values
            unique_values[col] = df[col].unique()
    
    return unique_values