如何计算具有非空值的列和行之间的交点

Question

Hey so the title might be hard to understand so basically here's a small sample of my DataFrame.

    A   B   C   D   E   F   G   H   J   K   action
0                       22                  noise
1                           68              junk
2                   93                      junk
3           80                              junk
4                                   57      noise

The actions column only has two values (noise and junk). For instance in the first initial row column 'F' has a value of 22 and it's action is noise, and I want to count how many times 'F' has a non-null value when action is 'noise' and 'F' when action is 'junk'. Of course I want to count this for all the other single letter columns also. So I want to have a dictionary that likely looks like this where the inner dictionary has counts per action.

{'F': {'noise': 1, 'junk': 0},
 'G': {'noise': 0, 'junk': 1},
 'E': {'noise': 0, 'junk': 1},
 'C': {'noise': 0, 'junk': 1},
 'J': {'noise': 1, 'junk': 0}
}

I've tried going through with df.iterrows() and df.notnull() but I can't seem to get the logic right.

edit - Updated the expected output.

Answer 1

使用notnull()来掩盖你的df ， groupby每个动作和简单的sum

df.iloc[:, :-1].notnull().astype(int).groupby(df.action).sum().to_dict()