python pandas 分组后 列上移

import pandas as pd
train_data = pd.read_csv(filepath_or_buffer='E:\\tmp\\2\\xuhao', sep='\t',encoding='utf-8',names=['id','xuhao', 'txt'])
# train_data.drop_duplicates(inplace=True)
df = pd.DataFrame(train_data)
df['new_data'] = df.groupby('id')['txt'].shift(-1)
# grouped['newxuhao']= grouped.groupby(['id']).cumcount()+1
# grouped = grouped.sort_values(['label'], ascending=True)
#
print(df.head(10))
df.to_csv('E:\\tmp\\2\\202008182_3.txt',
                  sep='\t',
                  encoding='utf-8',
                  header=None)