Pandas: occurrence matrix from one hot encoding from pandas dataframe

Question

I have a dataframe, it\'s in one hot format:

dummy_data = {\'a\': [0,0,1,0],\'b\': [1,1,1,0], \'c\': [0,1,0,1],\'d\': [1,1,1,0]}
data = pd.DataFrame(dummy_data)
         


        

Answer 1

You can have some fun with matrix math!

---

u = np.diag(np.ones(df.shape[1], dtype=bool))

df.T.dot(df) * (~u)

   a  b  c  d
a  0  1  0  1
b  1  0  1  3
c  0  1  0  1
d  1  3  1  0