Compute co-occurrence matrix by counting values in cells

Question

I have a dataframe like this

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

I want to get

  a         


        

Answer 1

You can do a multiplication using @ operator for numpy arrays.

df = pd.DataFrame(df.values.T @ df.values, df.columns, df.columns)