将类别转换为二进制列（连接类别列）答案

【问题标题】：Convert categories to binary columns (concat the category columns)将类别转换为二进制列（连接类别列）
【发布时间】：2023-01-10 02:19:30
【问题描述】：

想要将类别转换为列，连接到 df。类别列值应该是每行包含 0 或 1 的新列。

df = pd.DataFrame({"": [0,1,2,3],
                     "value1": ["ryan", "delta", "delta", "delta"], 
                     "category": ["teacher", "pilot", "engineer", "pilot"], 
                     "value2": [1, 1, 2, 3]})

答案 df 应该是：

finaldf = pd.DataFrame({"": [0,1,2,3],
                     "value1": ["ryan", "delta", "delta", "delta"], 
                     "category": ["teacher", "pilot", "engineer", "pilot"], 
                       "teacher":[1,0,0,0],
                       "pilot":[0,1,0,1],
                       "engineer": [0,0,1,0],
                     "value2": [1, 1, 2, 3]})

【问题讨论】：

标签： python pandas

【解决方案1】：

使用pd.get_dummies：

finaldf = pd.get_dummies(df, columns=["category"], prefix="", prefix_sep="")

输出：

     value1  value2  engineer  pilot  teacher
0  0   ryan       1         0      0        1
1  1  delta       1         0      1        0
2  2  delta       2         1      0        0
3  3  delta       3         0      1        0

【讨论】：