如何修复np。Pandas在哪里活动

Question

我的数据框看起来像-

id      marital_status       age        city1         city2
1           Married          32           7             64
2           Married          34           8             39
3           Single           53           0             72
4           Divorce          37           2             83
5           Divorce          42           10            52
6           Single           29           3             82
7           Married          37           8             64

数据帧的大小是2240万条记录

我的目标是基于条件语句我的最终数据帧看起来像-

id      marital_status       age        city1         city2        present
1           Married          32           12            64           1
2           Married          34           8             39           0
3           Single           53           0             72           0
4           Divorce          37           2             83           0
5           Divorce          42           10            52           0
6           Single           29           3             82           0
7           Married          37           8             64           1

到目前为止我所做的-

test_df = pd.read_csv('city.csv')

condition = ((test_df['city1'] >= 5) &\
            (test_df['marital_status'] == 'Married') &\
            (test_df['age'] >= 32))


test_df.loc[:, 'present'] = test_df.where(condition, 1)

但在“当前”列中有NA值

有人能帮我吗

Answer 1

它不是np.where函数，而是解决方案中的DataFrame.where

我认为你需要根据条件设定值：

test_df['present'] = np.where(condition, 1, 0)

或由^{}将True/False强制转换为1/0：

test_df['present'] = condition.astype(int)

---

print (test_df)
   id marital_status  age  city1  city2  present
0   1        Married   32     12     64        1
1   2        Married   34      8     39        1
2   3         Single   53      0     72        0
3   4        Divorce   37      2     83        0
4   5        Divorce   42     10     52        0
5   6         Single   29      3     82        0
6   7        Married   37      8     64        1