问在Python中创建交互矩阵

EN

frame= pd.DataFrame.from_records([('user1' ,'A') , ('user1','A'), ('user2' , 'A') , ('user3' ,'B')] , columns = ['user_id' , 'product_name'])

from scipy.sparse import csr_matrix
from pandas.api.types import CategoricalDtype
def incident_to_sparse_interaction_matrix(frame,user_column,item_column):

    #create datatypes to count and index your categorical data (like user_id , item_id)
    users = CategoricalDtype(sorted(frame[user_column].unique()), ordered=True)
    items = CategoricalDtype(sorted(frame[item_column].unique()), ordered=True)
    frame['score'] = 1  # add score column to fill the interaction matrix with this can be score of the movie or simple 1 as indicator variable
    row = frame[user_column].astype(users).cat.codes
    col = frame[item_column].astype(items).cat.codes
    sparse_matrix = csr_matrix((frame['score'], (row, col)), \
                               shape=(users.categories.size, items.categories.size))
    return sparse_matrix

collab_sparse = incident_to_sparse_interaction_matrix(frame , 'user_id' , 'product_name')
print(collab_sparse.toarray())

[[2 0]
 [1 0]
 [0 1]]