>  full_ratings =pd.concat(all_list).astype('Int64')
>  full_ratings[['fide_id','ID Number']] = all_ratings[['fide_id','ID Number']].fillna(0)
>  sum = full_ratings['fide_id'] + full_ratings['ID Number']   
>  full_ratings['ID PLAYER'] = full_ratings['fide_id'] + all_ratings['ID Number'] 
> full_ratings = full_ratings.drop(columns = ['fide_id','ID Number'])`

多亏了我自己，也只有我自己。