Data Science with Python Certification Data Science with Python (Basic) 2

Question 1

Which NumPy function creates an array of evenly spaced values over a specified interval?

Accepted Answer

np.linspace()

Answer

np.linspace() returns evenly spaced numbers over a specified interval, including both endpoints by default.

Question 2

In pandas, what does the method df.dropna() do by default?

Accepted Answer

Drops rows with any missing values

Answer

By default, df.dropna() removes any row that contains at least one NaN value (axis=0).

Question 3

What is the output of np.array([1,2,3]).reshape(3,1).shape?

Accepted Answer

(3,1)

Answer

reshape(3,1) converts the 1-D array into a 2-D column vector with 3 rows and 1 column, so shape is (3,1).

Question 4

Which pandas method is used to compute summary statistics (mean, std, min, max) for a DataFrame?

Accepted Answer

df.describe()

Answer

df.describe() generates descriptive statistics including count, mean, std, min, quartiles, and max for numeric columns.

Question 5

In Matplotlib, which function saves the current figure to a file?

Accepted Answer

plt.savefig()

Answer

plt.savefig('filename.png') saves the current figure to disk in the specified format.

Data Science with Python Certification Practice Test