def _is_numeric(df, column):
    """
    Helper function used to take a dataframe, a column name
    Returns True if the column is numerical, False otherwise

    Parameters
    --------
    file:
        a csv file
    column:
        a column name as a string


    Returns
    -------
    Bool
    """

    if str(df[column].dtypes) == 'int64' or \
       str(df[column].dtypes) == 'float64':
        return True
    else:
        return False