DA Data Analysis Tools and Programming 2

Question 1

What is the purpose of the pandas groupby() function?

Accepted Answer

Splitting data into groups and applying aggregate functions to each group

Answer

Sorting a DataFrame by column values

Answer

Merging two DataFrames

Answer

Filtering rows by condition

Question 2

In Python, what does the NumPy function np.mean() calculate?

Accepted Answer

Arithmetic mean of array elements

Answer

Median value of an array

Answer

Most frequently occurring value

Answer

Range of the array

Question 3

What is a Jupyter Notebook primarily used for?

Accepted Answer

Interactive data exploration combining code, output, and narrative text

Answer

Database administration

Answer

Version control of Python projects

Answer

Deploying machine learning models to production

Question 4

What Excel function counts cells that meet a specific condition?

Accepted Answer

COUNTIF

Answer

SUMIF

Answer

AVERAGEIF

Answer

IFERROR

Question 5

What does df.isnull().sum() return in pandas?

Accepted Answer

Number of missing values per column

Answer

Total number of rows in the DataFrame

Answer

Sum of all numeric values

Answer

Boolean mask of duplicate rows

Question 6

What is the purpose of the pd.merge() function in pandas?

Accepted Answer

Combine two DataFrames based on a common key column, similar to a SQL JOIN

Answer

Concatenate rows from two DataFrames

Answer

Remove duplicate rows

Answer

Reshape a DataFrame from wide to long format