可以使用merge：

out = pd.merge(df[df['Primary or Secondary'] == 'Primary'],
               df[df['Primary or Secondary'] == 'Secondary'],
               on='Visit ID', suffixes=('', '2'))

睡觉正在重新格式化：

out = out[['Visit ID', 'DX Code', 'DX Code2', 'Insurance', 'Insurance2']] 
          .rename(columns={'Insurance': 'Primary', 'Insurance2': 'Secondary'})

>>> df
   Visit ID  DX Code  DX Code2   Primary Secondary
0         1      123       234     Aetna  Affinity
1         2      789       456  Medicare       VNS