Converting between formats in SciPy - Mini Project: Build & Apply

Converting between formats

📖 Scenario: You work in a data science team that uses sparse matrices to save memory. Sparse matrices can be stored in different formats. You want to practice converting a sparse matrix from one format to another.

🎯 Goal: Create a sparse matrix in COO format, then convert it to CSR format, and finally print the CSR matrix.

📋 What You'll Learn

Create a COO sparse matrix with given data

Create a variable for the CSR format conversion

Convert the COO matrix to CSR format

Print the CSR matrix

💡 Why This Matters

🌍 Real World

Sparse matrices save memory when working with large datasets that have many zeros, such as text data or graphs.

💼 Career

Data scientists often convert between sparse matrix formats to optimize performance for different algorithms.

1

Create a COO sparse matrix

Import coo_matrix from scipy.sparse. Create a COO sparse matrix called coo with data [3, 1, 2], row indices [0, 1, 2], and column indices [0, 2, 1].

SciPy

# Your code here

Need a hint?

Use the coo_matrix constructor with a tuple of (data, (row, col)) arrays.

2

Create a variable for CSR conversion

Create a variable called csr and set it to None. This will hold the CSR format matrix.

SciPy

from scipy.sparse import coo_matrix
coo = coo_matrix(([3, 1, 2], ([0, 1, 2], [0, 2, 1])))
# Your code here

Need a hint?

Just create the variable csr and assign None to it.

3

Convert COO matrix to CSR format

Convert the COO matrix coo to CSR format and assign it to the variable csr. Use the tocsr() method.

SciPy

from scipy.sparse import coo_matrix
coo = coo_matrix(([3, 1, 2], ([0, 1, 2], [0, 2, 1])))
csr = None
# Your code here

Need a hint?

Use csr = coo.tocsr() to convert the matrix.

4

Print the CSR matrix

Print the variable csr to display the CSR sparse matrix.

SciPy

from scipy.sparse import coo_matrix
coo = coo_matrix(([3, 1, 2], ([0, 1, 2], [0, 2, 1])))
csr = coo.tocsr()
# Your code here

Need a hint?

Use print(csr) to show the CSR matrix.