Python pandas：选择列值为空/无/南的行
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时间：2020-08-19 23:20:34 来源:igfitidea点击:
Python pandas: selecting rows whose column value is null / None / nan
提问by zadrozny
How do I select those rows of a DataFrame whose value in a column is none?
如何选择列中值为 none 的 DataFrame 的那些行？
I've coded these to np.nanand can't match against this type.
我已经将这些编码为np.nan并且无法与这种类型匹配。
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: []
