Python 在对数据帧的多个列执行set_索引后，set_索引列将被删除，如何保留原始列？

你能帮我解决下面的问题吗？我需要转置一个数据帧，下面的代码工作正常，只是一个问题，set_索引中定义的所有列都被删除了。我不知道我哪里出错了。输入文件（df_pandas.csv）和输出文件（df_trt_set_index.csv，df_trt_pandas.csv）

请同时查找以下示例：

输入df_.csv：

trial_id|arm_id|re_randomized_arm_id|phase_id|treatment_id|phase|phase_duration|phase_duration_unit|phase_description|titration|titration_duration|titration_duration_unit|titration_target|titration_value|titration_unit|treatment_name|treatment_class|treatment_description|period_id|treatment_dose_avg|treatment_dose_avg_unit|treatment_dose_avg_type|treatment_median_no_of_cycles|treatment_mean_no_of_cycles|treatment_administration_days_act|mean_duration_of_treatment|median_duration_of_treatment|treatment_duration_units|period|period_duration|period_dur_unit|period_description|treatment_start_time|treatment_end_time|treatment_time_unit|treatment_dose|treatment_dose_units|treatment_frequency|treatment_roa|treatment_formulation|treatment_brand|treatment_prior|treatment_percent|treatment_administration_days_plan|treatment_administration_duration|treatment_administration_per_cycle|treatment_cycle_length|treatment_max_no_of_cycles
16|1|-999|1|1|Active|NA|NA|NA|No titration|NA|NA|NA|NA|NA|tocilizumab|Interleukin inhibitors|Patients were treated with Tocilizumab. The dose of TCZ used in patients was the range from 80 to 600 mg per time. Eight (53.3%) patients received TCZ in combination with MP. Five (33.3%) patients received TCZ administration twice or more|1|-999|NA|NA|-999|-999|NA|-999|-999|NA|NA|NA|NA|NA|-999|-999|NA|NA|NA|NA|NA|NA|NA|NA|-999|-999|NA|-999|-999|-999
173|1|-999|1|1|Active|NA|NA|NA|No titration|NA|NA|NA|NA|NA|lopinavir|Antivirals for treatment of HIV infections, combinations|Lopinavir/ritonavir 400/100 mg twice a day|1|-999|NA|NA|-999|-999|NA|-999|-999|NA|NA|NA|NA|NA|-999|-999|NA|400|mg|BID|NA|NA|NA|NA|-999|-999|NA|-999|-999|-999
274|2|-999|1|1|Active|NA|NA|NA|No titration|NA|NA|NA|NA|NA|control|ATC class not yet assigned|no targeted therapy|1|-999|NA|NA|-999|-999|d1-d3|-999|-999|NA|NA|NA|NA|NA|-999|-999|NA|NA|NA|NA|NA|NA|NA|NA|-999|3|NA|-999|-999|-999

df_trt_set_index.csv：

index|titration|titration_duration|titration_duration_unit|titration_target|titration_value|titration_unit|treatment_name|treatment_class|treatment_description|treatment_dose_avg|treatment_dose_avg_unit|treatment_dose_avg_type|treatment_median_no_of_cycles|treatment_mean_no_of_cycles|treatment_administration_days_act|mean_duration_of_treatment|median_duration_of_treatment|treatment_duration_units|treatment_start_time|treatment_end_time|treatment_time_unit|treatment_dose|treatment_dose_units|treatment_frequency|treatment_roa|treatment_formulation|treatment_brand|treatment_prior|treatment_percent|treatment_administration_days_plan|treatment_administration_duration|treatment_administration_per_cycle|treatment_cycle_length|treatment_max_no_of_cycles
0|No titration|NA|NA|NA|NA|NA|tocilizumab|Interleukin inhibitors|Patients were treated with Tocilizumab. The dose of TCZ used in patients was the range from 80 to 600 mg per time. Eight (53.3%) patients received TCZ in combination with MP. Five (33.3%) patients received TCZ administration twice or more|-999|NA|NA|-999|-999|NA|-999|-999|NA|-999|-999|NA|NA|NA|NA|NA|NA|NA|NA|-999|-999|NA|-999|-999|-999
1|No titration|NA|NA|NA|NA|NA|lopinavir|Antivirals for treatment of HIV infections, combinations|Lopinavir/ritonavir 400/100 mg twice a day|-999|NA|NA|-999|-999|NA|-999|-999|NA|-999|-999|NA|400|mg|BID|NA|NA|NA|NA|-999|-999|NA|-999|-999|-999
2|No titration|NA|NA|NA|NA|NA|control|ATC class not yet assigned|no targeted therapy|-999|NA|NA|-999|-999|d1-d3|-999|-999|NA|-999|-999|NA|NA|NA|NA|NA|NA|NA|NA|-999|3|NA|-999|-999|-999

最终输出df_trt_pandas.csv：

    trial_id_|arm_id_|re_randomized_arm_id_|phase_id_|period_id_|phase_|phase_duration_|phase_duration_unit_|phase_description_|period_|period_duration_|period_dur_unit_|period_description_|index_1|index_10|index_11|index_12|index_13|index_2|titration_1|titration_10|titration_11|titration_12|titration_13|titration_2|titration_duration_1|titration_duration_10|titration_duration_11|titration_duration_12|titration_duration_13|titration_duration_2|titration_duration_unit_1|titration_duration_unit_10|titration_duration_unit_11|titration_duration_unit_12|titration_duration_unit_13|titration_duration_unit_2|titration_target_1|titration_target_10|titration_target_11|titration_target_12|titration_target_13|titration_target_2|titration_value_1|titration_value_10|titration_value_11|titration_value_12|titration_value_13|titration_value_2|titration_unit_1|titration_unit_10|titration_unit_11|titration_unit_12|titration_unit_13|titration_unit_2|treatment_name_1|treatment_name_10|treatment_name_11|treatment_name_12|treatment_name_13|treatment_name_2|treatment_class_1|treatment_class_10|treatment_class_11|treatment_class_12|treatment_class_13|treatment_class_2|treatment_description_1|treatment_description_10|treatment_description_11|treatment_description_12|treatment_description_13|treatment_description_2|treatment_dose_avg_1|treatment_dose_avg_10|treatment_dose_avg_11|treatment_dose_avg_12|treatment_dose_avg_13|treatment_dose_avg_2|treatment_dose_avg_unit_1|treatment_dose_avg_unit_10|treatment_dose_avg_unit_11|treatment_dose_avg_unit_12|treatment_dose_avg_unit_13|treatment_dose_avg_unit_2|treatment_dose_avg_type_1|treatment_dose_avg_type_10|treatment_dose_avg_type_11|treatment_dose_avg_type_12|treatment_dose_avg_type_13|treatment_dose_avg_type_2|treatment_median_no_of_cycles_1|treatment_median_no_of_cycles_10|treatment_median_no_of_cycles_11|treatment_median_no_of_cycles_12|treatment_median_no_of_cycles_13|treatment_median_no_of_cycles_2|treatment_mean_no_of_cycles_1|treatment_mean_no_of_cycles_10|treatment_mean_no_of_cycles_11|treatment_mean_no_of_cycles_12|treatment_mean_no_of_cycles_13|treatment_mean_no_of_cycles_2|treatment_administration_days_act_1|treatment_administration_days_act_10|treatment_administration_days_act_11|treatment_administration_days_act_12|treatment_administration_days_act_13|treatment_administration_days_act_2|mean_duration_of_treatment_1|mean_duration_of_treatment_10|mean_duration_of_treatment_11|mean_duration_of_treatment_12|mean_duration_of_treatment_13|mean_duration_of_treatment_2|median_duration_of_treatment_1|median_duration_of_treatment_10|median_duration_of_treatment_11|median_duration_of_treatment_12|median_duration_of_treatment_13|median_duration_of_treatment_2|treatment_duration_units_1|treatment_duration_units_10|treatment_duration_units_11|treatment_duration_units_12|treatment_duration_units_13|treatment_duration_units_2|treatment_start_time_1|treatment_start_time_10|treatment_start_time_11|treatment_start_time_12|treatment_start_time_13|treatment_start_time_2|treatment_end_time_1|treatment_end_time_10|treatment_end_time_11|treatment_end_time_12|treatment_end_time_13|treatment_end_time_2|treatment_time_unit_1|treatment_time_unit_10|treatment_time_unit_11|treatment_time_unit_12|treatment_time_unit_13|treatment_time_unit_2|treatment_dose_1|treatment_dose_10|treatment_dose_11|treatment_dose_12|treatment_dose_13|treatment_dose_2|treatment_dose_units_1|treatment_dose_units_10|treatment_dose_units_11|treatment_dose_units_12|treatment_dose_units_13|treatment_dose_units_2|treatment_frequency_1|treatment_frequency_10|treatment_frequency_11|treatment_frequency_12|treatment_frequency_13|treatment_frequency_2|treatment_roa_1|treatment_roa_10|treatment_roa_11|treatment_roa_12|treatment_roa_13|treatment_roa_2|treatment_formulation_1|treatment_formulation_10|treatment_formulation_11|treatment_formulation_12|treatment_formulation_13|treatment_formulation_2|treatment_brand_1|treatment_brand_10|treatment_brand_11|treatment_brand_12|treatment_brand_13|treatment_brand_2|treatment_prior_1|treatment_prior_10|treatment_prior_11|treatment_prior_12|treatment_prior_13|treatment_prior_2|treatment_percent_1|treatment_percent_10|treatment_percent_11|treatment_percent_12|treatment_percent_13|treatment_percent_2|treatment_administration_days_plan_1|treatment_administration_days_plan_10|treatment_administration_days_plan_11|treatment_administration_days_plan_12|treatment_administration_days_plan_13|treatment_administration_days_plan_2|treatment_administration_duration_1|treatment_administration_duration_10|treatment_administration_duration_11|treatment_administration_duration_12|treatment_administration_duration_13|treatment_administration_duration_2|treatment_administration_per_cycle_1|treatment_administration_per_cycle_10|treatment_administration_per_cycle_11|treatment_administration_per_cycle_12|treatment_administration_per_cycle_13|treatment_administration_per_cycle_2|treatment_cycle_length_1|treatment_cycle_length_10|treatment_cycle_length_11|treatment_cycle_length_12|treatment_cycle_length_13|treatment_cycle_length_2|treatment_max_no_of_cycles_1|treatment_max_no_of_cycles_10|treatment_max_no_of_cycles_11|treatment_max_no_of_cycles_12|treatment_max_no_of_cycles_13|treatment_max_no_of_cycles_2
19|1|-999|1|1|Active|NA|NA|NA|NA|NA|NA|NA|237.0|1076.0|1110.0|563.0|1740.0|113.0|No titration|No titration|No titration|No titration|No titration|No titration|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|interferon alfa|thymosin|probiotics|heparin|nasal cannula support|lopinavir|Interferons|ATC class not yet assigned|ATC class not yet assigned|Heparin group|ATC class not yet assigned|Antivirals for treatment of HIV infections, combinations|All patients received antiviral therapy of alpha-interferon inhalation and lopinavir-ritonavir tablets|36.4% patients received Thymosin|47.3% patients received Probiotics|14.5% patients received Low molecular weight heparin|47.3% patients received Nasal cannula support|All patients received antiviral therapy of alpha-interferon inhalation and lopinavir-ritonavir tablets|-999|-999|-999|-999|-999|-999|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|NA|NA|NA|NA|NA|NA|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|NA|NA|NA|NA|NA|NA|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|Nasal|NA|NA|NA|NA|Oral|Solution|NA|NA|NA|NA|Tablet|NA|NA|NA|NA|NA|NA|Yes|Yes|Yes|Yes|Yes|Yes|100|36.4|47.3|14.5|47.3|100|-999|-999|-999|-999|-999|-999|NA|NA|NA|NA|NA|NA|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999

如果您从df_trt_set_index.csv中的上述示例输出中注意到，set_index中的所有列都被删除，索引即将出现，而df_trt_中的“u”和索引0…..索引13即将出现，请任何人提供帮助

    trial_id_|arm_id_|re_randomized_arm_id_|phase_id_|period_id_|phase_|phase_duration_|phase_duration_unit_|phase_description_|period_|period_duration_|period_dur_unit_|period_description_|index_1|index_10|index_11|index_12|index_13|index_2|titration_1|titration_10|titration_11|titration_12|titration_13|titration_2|titration_duration_1|titration_duration_10|titration_duration_11|titration_duration_12|titration_duration_13|titration_duration_2|titration_duration_unit_1|titration_duration_unit_10|titration_duration_unit_11|titration_duration_unit_12|titration_duration_unit_13|titration_duration_unit_2|titration_target_1|titration_target_10|titration_target_11|titration_target_12|titration_target_13|titration_target_2|titration_value_1|titration_value_10|titration_value_11|titration_value_12|titration_value_13|titration_value_2|titration_unit_1|titration_unit_10|titration_unit_11|titration_unit_12|titration_unit_13|titration_unit_2|treatment_name_1|treatment_name_10|treatment_name_11|treatment_name_12|treatment_name_13|treatment_name_2|treatment_class_1|treatment_class_10|treatment_class_11|treatment_class_12|treatment_class_13|treatment_class_2|treatment_description_1|treatment_description_10|treatment_description_11|treatment_description_12|treatment_description_13|treatment_description_2|treatment_dose_avg_1|treatment_dose_avg_10|treatment_dose_avg_11|treatment_dose_avg_12|treatment_dose_avg_13|treatment_dose_avg_2|treatment_dose_avg_unit_1|treatment_dose_avg_unit_10|treatment_dose_avg_unit_11|treatment_dose_avg_unit_12|treatment_dose_avg_unit_13|treatment_dose_avg_unit_2|treatment_dose_avg_type_1|treatment_dose_avg_type_10|treatment_dose_avg_type_11|treatment_dose_avg_type_12|treatment_dose_avg_type_13|treatment_dose_avg_type_2|treatment_median_no_of_cycles_1|treatment_median_no_of_cycles_10|treatment_median_no_of_cycles_11|treatment_median_no_of_cycles_12|treatment_median_no_of_cycles_13|treatment_median_no_of_cycles_2|treatment_mean_no_of_cycles_1|treatment_mean_no_of_cycles_10|treatment_mean_no_of_cycles_11|treatment_mean_no_of_cycles_12|treatment_mean_no_of_cycles_13|treatment_mean_no_of_cycles_2|treatment_administration_days_act_1|treatment_administration_days_act_10|treatment_administration_days_act_11|treatment_administration_days_act_12|treatment_administration_days_act_13|treatment_administration_days_act_2|mean_duration_of_treatment_1|mean_duration_of_treatment_10|mean_duration_of_treatment_11|mean_duration_of_treatment_12|mean_duration_of_treatment_13|mean_duration_of_treatment_2|median_duration_of_treatment_1|median_duration_of_treatment_10|median_duration_of_treatment_11|median_duration_of_treatment_12|median_duration_of_treatment_13|median_duration_of_treatment_2|treatment_duration_units_1|treatment_duration_units_10|treatment_duration_units_11|treatment_duration_units_12|treatment_duration_units_13|treatment_duration_units_2|treatment_start_time_1|treatment_start_time_10|treatment_start_time_11|treatment_start_time_12|treatment_start_time_13|treatment_start_time_2|treatment_end_time_1|treatment_end_time_10|treatment_end_time_11|treatment_end_time_12|treatment_end_time_13|treatment_end_time_2|treatment_time_unit_1|treatment_time_unit_10|treatment_time_unit_11|treatment_time_unit_12|treatment_time_unit_13|treatment_time_unit_2|treatment_dose_1|treatment_dose_10|treatment_dose_11|treatment_dose_12|treatment_dose_13|treatment_dose_2|treatment_dose_units_1|treatment_dose_units_10|treatment_dose_units_11|treatment_dose_units_12|treatment_dose_units_13|treatment_dose_units_2|treatment_frequency_1|treatment_frequency_10|treatment_frequency_11|treatment_frequency_12|treatment_frequency_13|treatment_frequency_2|treatment_roa_1|treatment_roa_10|treatment_roa_11|treatment_roa_12|treatment_roa_13|treatment_roa_2|treatment_formulation_1|treatment_formulation_10|treatment_formulation_11|treatment_formulation_12|treatment_formulation_13|treatment_formulation_2|treatment_brand_1|treatment_brand_10|treatment_brand_11|treatment_brand_12|treatment_brand_13|treatment_brand_2|treatment_prior_1|treatment_prior_10|treatment_prior_11|treatment_prior_12|treatment_prior_13|treatment_prior_2|treatment_percent_1|treatment_percent_10|treatment_percent_11|treatment_percent_12|treatment_percent_13|treatment_percent_2|treatment_administration_days_plan_1|treatment_administration_days_plan_10|treatment_administration_days_plan_11|treatment_administration_days_plan_12|treatment_administration_days_plan_13|treatment_administration_days_plan_2|treatment_administration_duration_1|treatment_administration_duration_10|treatment_administration_duration_11|treatment_administration_duration_12|treatment_administration_duration_13|treatment_administration_duration_2|treatment_administration_per_cycle_1|treatment_administration_per_cycle_10|treatment_administration_per_cycle_11|treatment_administration_per_cycle_12|treatment_administration_per_cycle_13|treatment_administration_per_cycle_2|treatment_cycle_length_1|treatment_cycle_length_10|treatment_cycle_length_11|treatment_cycle_length_12|treatment_cycle_length_13|treatment_cycle_length_2|treatment_max_no_of_cycles_1|treatment_max_no_of_cycles_10|treatment_max_no_of_cycles_11|treatment_max_no_of_cycles_12|treatment_max_no_of_cycles_13|treatment_max_no_of_cycles_2
19|1|-999|1|1|Active|NA|NA|NA|NA|NA|NA|NA|237.0|1076.0|1110.0|563.0|1740.0|113.0|No titration|No titration|No titration|No titration|No titration|No titration|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|interferon alfa|thymosin|probiotics|heparin|nasal cannula support|lopinavir|Interferons|ATC class not yet assigned|ATC class not yet assigned|Heparin group|ATC class not yet assigned|Antivirals for treatment of HIV infections, combinations|All patients received antiviral therapy of alpha-interferon inhalation and lopinavir-ritonavir tablets|36.4% patients received Thymosin|47.3% patients received Probiotics|14.5% patients received Low molecular weight heparin|47.3% patients received Nasal cannula support|All patients received antiviral therapy of alpha-interferon inhalation and lopinavir-ritonavir tablets|-999|-999|-999|-999|-999|-999|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|NA|NA|NA|NA|NA|NA|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|NA|NA|NA|NA|NA|NA|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|NA|Nasal|NA|NA|NA|NA|Oral|Solution|NA|NA|NA|NA|Tablet|NA|NA|NA|NA|NA|NA|Yes|Yes|Yes|Yes|Yes|Yes|100|36.4|47.3|14.5|47.3|100|-999|-999|-999|-999|-999|-999|NA|NA|NA|NA|NA|NA|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999|-999