Python 在Pandas 中通过GroupBy操作创建新列时出现KeyError

我试图通过对现有列执行一些操作来创建新列，但这在代码中引发了一个键错误.我try 通过使用df.Columns和Copy粘贴完全相同的名称来对其进行调试，但仍然收到相同的错误.我的代码如下:

def calculate_elasticity(group):
    sales_change = group['Primary Sales Quantity'].pct_change()
    price_change = group['MRP'].pct_change()
    
    elasticity = sales_change / price_change
    
    return elasticity

df['Variant-based Elasticity'] = df.groupby('Variant').transform(calculate_elasticity)

显示的错误是

---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
/usr/local/lib/python3.10/dist-packages/pandas/core/indexes/base.py in get_loc(self, key, method, tolerance)
   3801             try:
-> 3802                 return self._engine.get_loc(casted_key)
   3803             except KeyError as err:

16 frames
pandas/_libs/index_class_helper.pxi in pandas._libs.index.Int64Engine._check_type()

KeyError: 'Primary Sales Quantity'

The above exception was the direct cause of the following exception:

KeyError                                  Traceback (most recent call last)
/usr/local/lib/python3.10/dist-packages/pandas/core/indexes/base.py in get_loc(self, key, method, tolerance)
   3802                 return self._engine.get_loc(casted_key)
   3803             except KeyError as err:
-> 3804                 raise KeyError(key) from err
   3805             except TypeError:
   3806                 # If we have a listlike key, _check_indexing_error will raise

KeyError: 'Primary Sales Quantity'

我try 进行调试，下面是df.Columns的结果 Index(['Cal. year / month', 'Material', 'Product Name', 'MRP', 'Distribution Channel (Master)', 'Unnamed: 5', 'L1 Prod Category', 'L2 Prod Brand', 'L3 Prod Sub-Category', 'State', 'Primary Actual GSV Value', 'Primary Sales Qty (CS)', 'Secondary GSV', 'Secondary sales Qty(CS)', 'Primary Volume(MT/KL)', 'Secondary Volume(MT/KL)', 'Variant', 'Weight', 'Offers', 'Primary Sales Quantity'], dtype='object')个

并且结果为print(df['Primary Sales Quantity'])是

0          155
1        16953
2          455
3          138
4         2653
         ...  
14147        6
14148        1
14149     8428
14150      237
14151       24
Name: Primary Sales Quantity, Length: 14152, dtype: int64

我try 使用列名进行调试.我甚至可以使用该名称访问该列，只是在此函数中抛出了错误.