📅  最后修改于: 2022-03-11 14:45:46.261000             🧑  作者: Mango
代码示例3
In [5]: df = pd.DataFrame({'a':[1,2,np.nan], 'b':[np.nan,1,np.nan]})
In [6]: df.isna().sum()
Out[6]:
a 1
b 2
dtype: int64