def getUniqueValuesFromDataFrame(dataframe, col_nm, drop_na=True):
    """
    Args:

        dataframe is pandas dataframe, 
        col_nm is string name of column
    Returns:
        Returns a pandas Series with only unique values
        Removes None values if they exist
    """
    current_column = dataframe[col_nm].replace('nan',None)
    if drop_na:
        current_column = current_column.dropna()
    x = current_column.unique()
    return x