pandas 標簽映射成數值的幾種方法

1.

preprocessing.LabelEncoder()

import pandas as pd
from sklearn import preprocessing
le = preprocessing.LabelEncoder()

ddf = pd.DataFrame({"id":[1,2,3,1],"name":["a","b","c","a"],"age":[7,8,9,10]})
ddf[["id","name"]] = ddf[["id","name"]].fillna(0)
k = le.fit_transform(ddf["name"])
ddf["name"] = k
ddf

2. 

ddf["name"] = ddf["name"].astype("category").cat.codes