Session 3 - Sample Exam Qs

Question 1

import pandas as pd
data = pd.read_csv(“/content/sample_data/california_housing_test.csv”)
print(data.head())

This code aims to read a CSV file using pandas.

What is the purpose of the head() method, and why is it used in this context? - (2)

Answer 1

The purpose of the head() method in pandas is to display the first few rows of the DataFrame.

It provides a quick overview of the data structure and its contents, helping users understand the data better.

Question 2

Q1:
import pandas as pd
df = pd.read_csv(“content/sample_data/california_housing_test.csv”)
print(df.head())

Something is wrong with the following code. Explain what is wrong - and why.

Answer 2

The path name is missing a leading slash to indicate that it starts at the root.

Question 3

To convert from celsius to fahrenheit you multiply by 9/5 and add 32. What is wrong with the following code? How might you fix it?

Note - there are two potential issues here - try to make the conversion as accurate as possible. - (2)

Answer 3

First, the list is made of strings but you are trying to multiply them by a number.

Second, you append ‘C’ not ‘F’ to the list so you never store the Fahrenheit value –> So, The code indeed appends the original Celsius value (C) to the list instead of the calculated Fahrenheit value (F), so it doesn’t store the converted Fahrenheit temperatures.

Question 4

Password hell. What is the matter with this code?

Answer 4

The input statement is not in the loop so if you get it wrong once, you enter an infinite loop.

Question 5

s = “Python_Data_Science”
words = s.split(‘-‘)
print(words)

I’m trying to split the string ‘s’ into individual words. What is going wrong?

Answer 5

It’s splitting on a hyphen (-) but the string has underscores in it (_)

Question 6

Q3.5
I’m trying to read in a file using the Python csv reader. I think I almost have it but it doesn’t quite work…

Can you see what is wrong?

Answer 6

You should parse each row in csv_reader. csv_file does not exist