How to create feature with condition by using where()?-CodePudding

I am encoding my categorical data in column "Gender" by get_dummies()
Data at begining
Next, I have to create new feature isMale by using where() This feature should show gender by value(0 and 1), if gender is "female" than isMale equals to 0, and analogical gender="male" than isMale=1
And this feature should swap my "Gender" or just concatenate to my dataset

I don't get how to use where() method for creating feature

CodePudding user response：

you don't need np.where. since you're assigning boolean value, just check if Gender= Male is True or False, then convert True/False to int will get you 0 and 1

df['isMale'] = df['Gender'].eq('Male').astype(int)

CodePudding user response：

To replace your gender column:

import numpy as np
import pandas as pd


df['Gender'] = np.where(df['Gender'] == "Male", 1, 0)

To add a new column:

import numpy as np
import pandas as pd


df['isMale'] = np.where(df['Gender'] == "Male", 1, 0)

CodePudding user response：

Use assign and then the np.where

import numpy as np
import pandas as pd

...


df = df.assign(
    isMale=np.where(df['Gender'] == 'Female', 0, 1)
)