我如何在pandas中修复这个错误，在那里我需要找到具有最高特征的元素？

Question

这是我的代码。我需要找到速度最快的元素(精灵宝可梦)，HP，攻防。它们是有序的，最强的在上面。我不知道错误是从哪里来的。

     def strongestPokemon():
  strongPokemon_df = pd.DataFrame()
  each_type_df = []

  for type2 in pokemon_data['Type 2'].unique():
      sub_type = pokemon_data[pokemon_data['Type 2'] == type2]
      sub_type.sort_values(by=['HP','Attack','Defense','Speed'],ascending=[False,False,False,False],inplace=True)
      sub_type.reset_index(drop=True,inplace=True)
      top_pokemon = sub_type.loc[1]
      each_type_df.append(top_pokemon)

  strongPokemon_df = pd.DataFrame(each_type_df,columns=pk_data.columns)

  return strongPokemon_df

pk_strongest = strongestPokemon()
pk_strongest

这些是我得到的错误。很抱歉问了这么长的问题。我不确定为什么会发生这个错误。

   ValueError: 1 is not in range

During handling of the above exception, another exception occurred:

KeyError                                  Traceback (most recent call last)
6 frames
<ipython-input-87-fe71fd5a4e0f> in <module>()
     14   return strongPokemon_df
     15 
---> 16 pk_strongest = strongestPokemon()
     17 pk_strongest

<ipython-input-87-fe71fd5a4e0f> in strongestPokemon()
      7       sub_type.sort_values(by=['HP','Attack','Defense','Speed'],ascending=[False,False,False,False],inplace=True)
      8       sub_type.reset_index(drop=True,inplace=True)
----> 9       top_pokemon = sub_type.loc[1]
     10       each_type_df.append(top_pokemon)
     11 

/usr/local/lib/python3.6/dist-packages/pandas/core/indexing.py in __getitem__(self, key)
   1766 
   1767             maybe_callable = com.apply_if_callable(key, self.obj)
-> 1768             return self._getitem_axis(maybe_callable, axis=axis)
   1769 
   1770     def _is_scalar_access(self, key: Tuple):

/usr/local/lib/python3.6/dist-packages/pandas/core/indexing.py in _getitem_axis(self, key, axis)
   1963         # fall thru to straight lookup
   1964         self._validate_key(key, axis)
-> 1965         return self._get_label(key, axis=axis)
   1966 
   1967 

/usr/local/lib/python3.6/dist-packages/pandas/core/indexing.py in _get_label(self, label, axis)
    623             raise IndexingError("no slices here, handle elsewhere")
    624 
--> 625         return self.obj._xs(label, axis=axis)
    626 
    627     def _get_loc(self, key: int, axis: int):

/usr/local/lib/python3.6/dist-packages/pandas/core/generic.py in xs(self, key, axis, level, drop_level)
   3535             loc, new_index = self.index.get_loc_level(key, drop_level=drop_level)
   3536         else:
-> 3537             loc = self.index.get_loc(key)
   3538 
   3539             if isinstance(loc, np.ndarray):

/usr/local/lib/python3.6/dist-packages/pandas/core/indexes/range.py in get_loc(self, key, method, tolerance)
    350                 return self._range.index(new_key)
    351             except ValueError:
--> 352                 raise KeyError(key)
    353         return super().get_loc(key, method=method, tolerance=tolerance)
    354 

KeyError: 1

Answer 1

尝试：

top_pokemon = sub_type.iloc[1]

iloc用于传递索引时，因为您想要第一行，所以使用：

top_pokemon = sub_type.iloc[0]