Pandas warning SettingWithCopyWarning: A value is trying to be set on a copy of a slice from a DataFrame

Asked Jul 09 '20 at 11:11

Active Jul 09 '20 at 11:11

Viewed 9 times

I can't seem to understand why I am getting a warning from my pandas code below: I am trying to convert the column 'Sex' in the titanic.csv dataset to numeric using the code below:

from sklearn import preprocessing
label_encoding = preprocessing.LabelEncoder()
titanic_df['Sex'] =label_encoding.fit_transform(titanic_df['Sex'].astype(str))
titanic_df.head()

I get this warning:

<ipython-input-41-45071618b7c1>:4: SettingWithCopyWarning: 
A value is trying to be set on a copy of a slice from a DataFrame.
Try using .loc[row_indexer,col_indexer] = value instead

See the caveats in the documentation: https://pandas.pydata.org/pandas-docs/stable/user_guide/indexing.html#returning-a-view-versus-a-copy
  titanic_df['Sex'] =label_encoding.fit_transform(titanic_df['Sex'].astype(str))

How do I format the code to avoid getting errors?

edited Jul 09 '20 at 11:11

asked Jul 09 '20 at 11:11

Alex

How is created `titanic_df` ? – jezrael Jul 09 '20 at 11:11
like this: `titanic_df =pd.read_csv('datasets/train.csv')` – Alex Jul 09 '20 at 11:15
super, then later was no filtration? – jezrael Jul 09 '20 at 11:15
I've seen the related post and read it but can't seem to get an answer to the question – Alex Jul 09 '20 at 11:16
I've also done some data cleaning: `titanic_df.drop(['PassengerId', 'Name', 'Ticket', 'Cabin'], 'columns', inplace=True)` – Alex Jul 09 '20 at 11:16
Try `titanic_df.loc[:, 'Sex']=...` instead of `titanic_df['Sex']=...`. – Ala Tarighati Jul 09 '20 at 11:17
Use `titanic_df = titanic_df.drop(['PassengerId', 'Name', 'Ticket', 'Cabin'], 'columns').copy()` – jezrael Jul 09 '20 at 11:17
I used these two: `titanic_df[titanic_df.isnull().any(axis=1)].count()` `titanic_df=titanic_df.dropna()` Should I replace with your code above? – Alex Jul 09 '20 at 11:19
Like dupe say if some filtration like `drop` is necessary add `.copy()` – jezrael Jul 09 '20 at 11:28

Pandas warning SettingWithCopyWarning: A value is trying to be set on a copy of a slice from a DataFrame

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