如何根据上面的行删除行?蟒蛇 pandas [英] How to delete row based on row above? Python Pandas

问题描述

我有一个看起来像这样的数据集:

I have a dataset which looks like this:

df = pd.DataFrame({'a': [1,1,1, 2, 3, 3, 4], 'b': [1,np.nan, np.nan, 2, 3, np.nan, 4]})

我正在寻找删除本质上在下一行中具有np.nan的所有行.我不知道如何执行此操作，因为我不知道如何基于其他行删除行.

I'm looking to delete all rows which have np.nan in the next proceeding row essentially. I can't figure out how to do this because I don't know how to delete rows based on other rows.

推荐答案

您要查找下一行所有具有np.nan的行.为此使用shift:

You want to find all the rows that have a np.nan in the next row. Use shift for that:

df.shift().isnull()

       a      b
0   True   True
1  False  False
2  False   True
3  False   True
4  False  False
5  False  False
6  False   True

然后，您要弄清楚该行中是否有任何内容，因此您希望将其简化为单个布尔掩码.

Then you want to figure out if anything in that row was nan, so you want to reduce this to a single boolean mask.

df.shift().isnull().any(axis=1)

0     True
1    False
2     True
3     True
4    False
5    False
6     True
dtype: bool

然后只需删除列:

df.drop(df.shift().isnull().any(axis=1))

   a   b
2  1 NaN
3  2   2
4  3   3
5  3 NaN
6  4   4

这篇关于如何根据上面的行删除行?蟒蛇 pandas 的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！