Adding a column in a pandas df from an if in another column

Question

I am trying to make two one hot columns. I have in my df a column X_train["Sex"] which is either "male" or "female". I want to make a new column X_train["male"] with the value 1 if the "Sex" column was male and 0 if it was female (and the oposite in X_train["female"])

I tried this :

for sex in X_train["Sex"]: 
if sex=="male":
    X_train["male"]=1
    X_train["female"]=0
else:
    
    X_train["male"]=0
    X_train["female"]=1

but i get this as a result :

enter image description here