Encoding categorical columns I: LabelEncoder
Now that you've seen what will need to be done to get the housing data ready for XGBoost, let's go through the process step-by-step.
First, you will need to fill in missing values - as you saw previously, the column LotFrontage has many missing values. Then, you will need to encode any categorical columns in the dataset using one-hot encoding so that they are encoded numerically. You can watch this video from Supervised Learning with scikit-learn for a refresher on the idea. 
The data has five categorical columns: MSZoning, PavedDrive, Neighborhood, BldgType, and HouseStyle. Scikit-learn has a LabelEncoder function that converts the values in each categorical column into integers. You'll practice using this here.
Este ejercicio forma parte del curso
Extreme Gradient Boosting with XGBoost
Instrucciones del ejercicio
- Import 
LabelEncoderfromsklearn.preprocessing. - Fill in missing values in the 
LotFrontagecolumn with0using.fillna(). - Create a boolean mask for categorical columns. You can do this by checking for whether 
df.dtypesequalsobject. - Create a 
LabelEncoderobject. You can do this in the same way you instantiate any scikit-learn estimator. - Encode all of the categorical columns into integers using 
LabelEncoder(). To do this, use the.fit_transform()method oflein the provided lambda function. 
Ejercicio interactivo práctico
Prueba este ejercicio y completa el código de muestra.
# Import LabelEncoder
____
# Fill missing values with 0
df.LotFrontage = ____
# Create a boolean mask for categorical columns
categorical_mask = (____ == ____)
# Get list of categorical column names
categorical_columns = df.columns[categorical_mask].tolist()
# Print the head of the categorical columns
print(df[categorical_columns].head())
# Create LabelEncoder object: le
le = ____
# Apply LabelEncoder to categorical columns
df[categorical_columns] = df[categorical_columns].apply(lambda x: ____(x))
# Print the head of the LabelEncoded categorical columns
print(df[categorical_columns].head())