Data Science with Python Certification Data Science with Python (Basic) 3

Question 1

What is broadcasting in NumPy?

Accepted Answer

A mechanism that allows arithmetic operations on arrays of different shapes

Answer

Broadcasting allows NumPy to perform element-wise operations on arrays with different shapes by virtually expanding the smaller array.

Question 2

In a pandas DataFrame, what is the difference between loc and iloc?

Accepted Answer

loc uses label-based indexing; iloc uses integer position-based indexing

Answer

loc selects data using row/column labels, while iloc selects using integer positions (0-based).

Question 3

Which Python library is primarily used for data manipulation and analysis with labeled data structures?

Accepted Answer

pandas

Answer

pandas provides DataFrame and Series structures designed for labeled, tabular data manipulation and analysis.

Question 4

What does a confusion matrix diagonal represent in a classification problem?

Accepted Answer

Correctly classified samples

Answer

The main diagonal of a confusion matrix shows counts where the predicted class equals the true class (correct predictions).

Question 5

Which NumPy operation computes the dot product of two 1-D arrays?

Accepted Answer

np.dot(a,b)

Answer

np.dot(a,b) computes the dot (inner) product of two 1-D arrays, resulting in a scalar.

Data Science with Python Certification Practice Test