按熊貓分組數據框總和

Question

df：

a b class
0 0  +
0 1  +
1 0  -

預期輸出：

group each column based on class value and find the count, 
as in taking column 'a' as example the count should be 2 
for class '+' and 1 for class '-'

碼：

grp = df.groupby(df.class, axis=1).sum()

得到我什至不理解的錯誤。 對熊貓來說是新手，任何建議都很棒。

Answer 1

嘗試這個：

print(sample.groupby('class').count())