0
$\begingroup$

I am working on a machine learning practice problem, from https://datahack.analyticsvidhya.com/contest/practice-problem-big-mart-sales-iii/#ProblemStatement

I want to replace the null values in the column 'Item_Weight' and for that I am using the mean values given by a pivot_table where I calculated the mean of 'Item_Weight' and grouping the mean by column 'Item_Identifier' of the dataset.

item_weight_mean = ds.pivot_table(values='Item_Weight',columns='Item_Identifier')
loc2 = ds['Item_Weight'].isnull()
ds.loc[loc2, 'Item_Weight'] = ds.loc[loc2, 'Item_Identifier'].apply(lambda x: item_weight_mean[x])

I am getting an error for the same code.

(key)
-> 2902             indexer = self.columns.get_loc(key)
   2903             if is_integer(indexer):
   2904                 indexer = [indexer]

D:\Important Applications\anaconda3\lib\site-packages\pandas\core\indexes\base.py in get_loc(self, key, method, tolerance)
   2895                 return self._engine.get_loc(casted_key)
   2896             except KeyError as err:
-> 2897                 raise KeyError(key) from err
   2898 
   2899         if tolerance is not None:

KeyError: 'FDN52'

How do I remove this error?

Improve this question
$\endgroup$
1
  • $\begingroup$ I suggest adding some more output, for example what does the first 5 rows of item_weight_mean look like? $\endgroup$ Commented May 15, 2021 at 19:48

2 Answers 2

Reset to default
0
$\begingroup$

Consider using df.fillna(). That has a variety of options to replace nans with values of choices. You can apply it on either the complete data frame or on specific columns (I.e Series).

Improve this answer
$\endgroup$
1
  • $\begingroup$ But using fillna(), I cannot repalce the values mean of column grouped by some other feature. Can this be done using fillna()? $\endgroup$ Commented May 10, 2021 at 14:58
0
$\begingroup$

The output of the pivot_table function is a dataframe, which you can confirm using the type command.

Secondly, the syntax item_weight_mean[x] is a way of indexing columns, whereas I suspect you want to index rows.

So the error message states that the key FDN52 Isn't a column I believe.

Improve this answer
$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.