from sklearn.preprocessing import LabelEncoder 
from sklearn.preprocessing import onehotencoder 

data = ["cold", "cold", "warm", "cold", "hot", "hot", "warm", "cold", "warm", "hot"]
data = pd.DataFrame(data)
data.columns = ["温度"]  
label_encoder = LabelEncoder()
data["温度"] = label_encoder.fit_transform(data["温度"]) 

onehot_encoder = preprocessing.OneHotEncoder(sparse=False) 
data["温度"] = onehot_encoder.fit_transform(data[["温度"]])