Python Pandas查找所有值均为NaN的所有行 [英] Python Pandas find all rows where all values are NaN

问题描述

所以我有一个包含5列的数据框.我想提取所有列均为NaN的索引.我正在使用此代码:

So I have a dataframe with 5 columns. I would like to pull the indices where all of the columns are NaN. I was using this code:

nan = pd.isnull(df.all)

但这只是返回false，因为从逻辑上讲并非并非数据框中的所有值都为null.有成千上万的条目，所以我宁愿不必遍历并检查每个条目.谢谢！

but that is just returning false because it is logically saying no not all values in the dataframe are null. There are thousands of entries so I would prefer to not have to loop through and check each entry. Thanks!

推荐答案

应为:

df.isnull().all(1)

index的访问方式如下:

df.index[df.isnull().all(1)]

演示

np.random.seed([3,1415])
df = pd.DataFrame(np.random.choice((1, np.nan), (10, 2)))
df

idx = df.index[df.isnull().all(1)]
nans = df.ix[idx]
nans

代码

np.random.seed([3,1415])
df = pd.DataFrame(np.random.choice((1, np.nan), (10000, 5)))

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