Dataframes and manipulating data

Question 1

What does df.head() do?

Answer 1

Returns the first 5 rows of the DataFrame.

Question 2

How to show the last 5 rows of a DataFrame?

Answer 2

Use df.tail().

Question 3

How to get column names?

Answer 3

Use df.columns.

Question 4

How to get row indices?

Answer 4

Use df.index.

Question 5

What does df.info() display?

Answer 5

Summarizes DataFrame structure (data types, non-null counts).

Question 6

What is the purpose of df.describe()?

Answer 6

Generates statistical summary (mean, std, min, max, etc.).

Question 7

How to count unique values per column?

Answer 7

Use df.nunique().

Question 8

How to filter rows where height is over 200 cm?

Answer 8

Use df[df[‘height_cm’] > 200].

Question 9

How to select specific rows and columns using labels?

Answer 9

Use df.loc[rows, columns].

Question 10

How to sort by ‘Units Sold’ in descending order?

Answer 10

Use df.sort_values(‘Units Sold’, ascending=False).

Question 11

How to iterate over DataFrame rows?

Answer 11

Use df.iterrows().

Question 12

How to load a CSV file?

Answer 12

Use pd.read_csv(‘file_path’).

Question 13

How to filter rows where ‘name’ contains ‘Mike’?

Answer 13

Use df[df[‘name’].str.contains(‘Mike’)].

Question 14

How to query rows where born_country is ‘IND’ or ‘USA’?

Answer 14

Use df.query(‘born_country == "IND" or born_country == "USA"’).

Question 15

What does df.shape return?

Answer 15

A tuple representing (rows, columns).