按等于无值的列值条件在DataFrame中删除行

Question

我有一个数据框，其中有一列“状态”，我尝试删除其中“状态”列包含“无”值的所有行。

我确实是这样的：

oppty_oppline.dropna(subset = ['status'])

但是“ None”值没有被删除。 我这样验证：

oppty_oppline.status.unique()

结果：

array(['Cancelled by ', 'Cancelled by Customer',
       'Account not selected', None,
       'Won - Deliver & Validate by ', 'Lost',
       'Won - Deliver & Validate by Partner',
       'Won-Deliver&Validate by ',
       'Cancelled by ', 'Won by another',
       'Won- Deliver and Validate by Partner',
       'Won – Deliver & Validate by Partner'], dtype=object)

我看到'None'值不被视为字符串。

有什么想法请帮我吗？

谢谢

Answer 1

如果None值，则工作正常：

a = np.array(['Cancelled by ', 'Cancelled by Customer',
       'Account not selected', None])

oppty_oppline = pd.DataFrame({'status':a})
print (oppty_oppline)
                  status
0          Cancelled by 
1  Cancelled by Customer
2   Account not selected
3                   None

df = oppty_oppline.dropna(subset = ['status'])
print (df)
                  status
0          Cancelled by 
1  Cancelled by Customer
2   Account not selected

但是如果字符串None需要通过boolean indexing删除行：

a = np.array(['Cancelled by ', 'Cancelled by Customer',
       'Account not selected', 'None'])

oppty_oppline = pd.DataFrame({'status':a})
print (oppty_oppline)
                  status
0          Cancelled by 
1  Cancelled by Customer
2   Account not selected
3                   None

#not remove None, because string
df = oppty_oppline.dropna(subset = ['status'])
print (df)
0          Cancelled by 
1  Cancelled by Customer
2   Account not selected
3                   None

---

df = oppty_oppline[oppty_oppline.status != 'None']
print (df)
0          Cancelled by 
1  Cancelled by Customer
2   Account not selected