如何选择DataFrame中某一列值为None的行?
我已将其编码为np.nan
,无法匹配这种类型。
In [1]: import numpy as np
In [2]: import pandas as pd
In [3]: df = pd.DataFrame([[1, 2, 3], [3, 4, None]])
In [4]: df
Out[4]:
0 1 2
0 1 2 3.0
1 3 4 NaN
In [5]: df = df.fillna(np.nan)
In [6]: df
Out[6]:
0 1 2
0 1 2 3.0
1 3 4 NaN
In [7]: df.iloc[1][2]
Out[7]: nan
In [8]: df.iloc[1][2] == np.nan
Out[8]: False
In [9]: df[df[2] == None]
Out[9]:
Empty DataFrame
Columns: [0, 1, 2]
Index: []
df[df[2] == None]
?为什么在使用 fillna(np.nan) 编码 NaN 后,np.nan 不能与自身匹配? - zadroznyfillna(np.nan)
将会用 NaN 替换 NaN ;) - MaxU - stand with Ukraine