Question

# python

How to convert a dataframe column into sparse matrix?

For example there is one column [1,2,3]

I want to convert it into:

1 0 0

0 1 0

0 0 1

Answer 1

Note: Done accordingly. Please comment for further help. Please uprate.

Code:

import pandas as pd
from scipy import sparse
# here column is the column for which we want sparse matrix
df = pd.DataFrame({'tag1': ['sean', 'udi', 'bogdan'], 'tag2': ['a', 'b', 'c'], 'column': [1,2,3]})
# tag1 -> rows, tag2 -> columns that will help for creating sparse matrix.
df.set_index(['tag1', 'tag2'], inplace=True)

mat = sparse.coo_matrix((df.column, (df.index.codes[0], df.index.codes[1]))) #here you can use ([0,1,2],[2,1,0]) as well.
print(mat.todense())

Code Snapshot:

Output: