我有一个30列的cassandra表和一个dataframe，它包含用户选择的任意数量的列，或者用户上传的csv文件。
例如，我的cassandra表有30个频道名，如频道1、频道2。。channel_30和几个额外的列，如product、region等，我的Dataframe有5个通道名，如channel_1、channel_2..channel_5和2个额外的列：date和model name如何编写一个insert查询，该查询遍历我的Dataframe列并按如下方式创建查询：

data = pd.DataFrame()
...
for _, row in data.iterrows():

            session.execute("""INSERT INTO cass_table (product, region , model, date, (channel names in dataframe ex.channel_1, \
                    channel_2, channel_3, channel_4, channel_5) \
                    VALUES (%s, %s, %s, %s, <no of channels: %s, %s, %s, %s, %s>)""" ,\
                    (product, region, row['model_name'], row['date'], <other remaining columns like row["channel_1"], row["channel_2"],\
                    row["channel_3"], row["channel_4"], row["channel_5"]>))

我试过这个：

channel_list = ['channel_1', 'channel_2', 'channel_3', 'channel_4', 'channel_5']
session.execute("""INSERT INTO cass_table(product, region , model, date, \
                    """ + str(' ,'.join('channel_{}_cont'.format(i) for i,c in enumerate(channel_list, 1))) + """) ,\
                    VALUES (%s, %s, %s, %s"""+ str(''.join(', %s'*no_of_channels)), """)""" \
                    (product, region, row['model_name'], row[date_col] , ','.join(row["'"+channel_list+"'"])))

但这会产生错误：“str对象不可调用”
我该怎么做？