pandas 熊猫滚动应用缺失数据
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/13405611/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Pandas rolling apply with missing data
提问by Mahesh
I want to do a rolling computation on missing data.
我想对丢失的数据进行滚动计算。
Sample Code: (For sake of simplicity I'm giving an example of a rolling sum but I want to do something more generic.)
示例代码：（为了简单起见，我举了一个滚动总和的例子，但我想做一些更通用的事情。）
foo = lambda z: z[pandas.notnull(z)].sum()
x = np.arange(10, dtype="float")
x[6] = np.NaN
x2 = pandas.Series(x)
pandas.rolling_apply(x2, 3, foo)
which produces:
它产生：
0 NaN
1 NaN
2 3
3 6
4 9
5 12
6 NaN
7 NaN
8 NaN
9 24
I think that during the "rolling", window with missing data is being ignored for computation. I'm looking to get a result along the lines of:
我认为在“滚动”期间，缺少数据的窗口被忽略以进行计算。我希望得到以下结果：
0 NaN
1 NaN
2 3
3 6
4 9
5 12
6 9
7 12
8 15
9 24
回答by Chang She
In [7]: pandas.rolling_apply(x2, 3, foo, min_periods=2)
Out[7]:
0 NaN
1 1
2 3
3 6
4 9
5 12
6 9
7 12
8 15
9 24
